Philosophy is the study of general and fundamental problems, such as those connected with reality, existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational argument. In more casual speech, by extension, "philosophy" can refer to "the most basic beliefs, concepts, and attitudes of an individual or group".
The word "philosophy" comes from the Ancient Greek φιλοσοφία (philosophia), which literally means "love of wisdom". The introduction of the terms "philosopher" and "philosophy" has been ascribed to the Greek thinker Pythagoras.
Areas of inquiry 1
- Epistemology 1.1
- Logic 1.2
- Metaphysics 1.3
- Ethics and political philosophy 1.4
- Aesthetics 1.5
- Specialized branches 1.6
Ancient philosophy 2.1
- Egypt and Babylon 2.1.1
- Ancient Chinese 2.1.2
- Ancient Graeco-Roman 2.1.3
- Ancient Indian 2.1.4
- Ancient Persian 2.1.5
5th–16th centuries 2.2
- Medieval 220.127.116.11
- Renaissance 18.104.22.168
- East Asia 2.2.2
- India 2.2.3
- Middle East 2.2.4
- Europe 2.2.1
17th–20th centuries 2.3
- Early modern philosophy 2.3.1
- 19th-century philosophy 2.3.2
- 20th-century philosophy 2.3.3
- Ancient philosophy 2.1
Major traditions 3
- German idealism 3.1
- Pragmatism 3.2
- Phenomenology 3.3
- Existentialism 3.4
- Structuralism and post-structuralism 3.5
- The analytic tradition 3.6
- Applied philosophy 4
- See also 5
- References 6
Further reading 7
- Introductions 7.1
- Topical introductions 7.2
- Anthologies 7.3
- Reference works 7.4
- External links 8
Areas of inquiry
Philosophy is divided into many sub-fields. These include epistemology, logic, metaphysics, ethics, and aesthetics. Some of the major areas of study are considered individually below.
Skepticism is the position which questions the possibility of completely justifying any truth. The regress argument, a fundamental problem in epistemology, occurs when, in order to completely prove any statement, its justification itself needs to be supported by another justification. This chain can do three possible options, all of which are unsatisfactory according to the Münchhausen trilemma. One option is infinitism, where this chain of justification can go on forever. Another option is foundationalism, where the chain of justifications eventually relies on basic beliefs or axioms that are left unproven. The last option, such as in coherentism, is making the chain circular so that a statement is included in its own chain of justification.
Rationalism is the emphasis on reasoning as a source of knowledge. Empiricism is the emphasis on observational evidence via sensory experience over other evidence as the source of knowledge. Rationalism claims that every possible object of knowledge can be deduced from coherent premises without observation. Empiricism claims that at least some knowledge is only a matter of observation. For this, Empiricism often cites the concept of tabula rasa, where individuals are not born with mental content and that knowledge builds from experience or perception. Epistemological solipsism is the idea that the existence of the world outside the mind is an unresolvable question.
Parmenides (fl. 500 BC) argued that it is impossible to doubt that thinking actually occurs. But thinking must have an object, therefore something beyond thinking really exists. Parmenides deduced that what really exists must have certain properties—for example, that it cannot come into existence or cease to exist, that it is a coherent whole, that it remains the same eternally (in fact, exists altogether outside time). This is known as the third man argument. Plato (427–347 BC) combined rationalism with a form of realism. The philosopher's work is to consider being, and the essence (ousia) of things. But the characteristic of essences is that they are universal. The nature of a man, a triangle, a tree, applies to all men, all triangles, all trees. Plato argued that these essences are mind-independent "forms", that humans (but particularly philosophers) can come to know by reason, and by ignoring the distractions of sense-perception.
Modern rationalism begins with Descartes. Reflection on the nature of perceptual experience, as well as scientific discoveries in physiology and optics, led Descartes (and also Locke) to the view that we are directly aware of ideas, rather than objects. This view gave rise to three questions:
- Is an idea a true copy of the real thing that it represents? Sensation is not a direct interaction between bodily objects and our sense, but is a physiological process involving representation (for example, an image on the retina). Locke thought that a "secondary quality" such as a sensation of green could in no way resemble the arrangement of particles in matter that go to produce this sensation, although he thought that "primary qualities" such as shape, size, number, were really in objects.
- How can physical objects such as chairs and tables, or even physiological processes in the brain, give rise to mental items such as ideas? This is part of what became known as the mind-body problem.
- If all the contents of awareness are ideas, how can we know that anything exists apart from ideas?
Descartes tried to address the last problem by reason. He began, echoing Parmenides, with a principle that he thought could not coherently be denied: I think, therefore I am (often given in his original Latin: Cogito ergo sum). From this principle, Descartes went on to construct a complete system of knowledge (which involves proving the existence of God, using, among other means, a version of the ontological argument). His view that reason alone could yield substantial truths about reality strongly influenced those philosophers usually considered modern rationalists (such as Baruch Spinoza, Gottfried Leibniz, and Christian Wolff), while provoking criticism from other philosophers who have retrospectively come to be grouped together as empiricists.
Logic is the study of the principles of correct reasoning. Arguments use either deductive reasoning or inductive reasoning. Deductive reasoning is when, given certain statements (called premises), other statements (called conclusions) are unavoidably implied. Rules of inferences from premises include the most popular method, modus ponens, where given “A” and “If A then B”, then “B” must be concluded. A common convention for a deductive argument is the syllogism. An argument is termed valid if its conclusion does follow from its premises, whether the premises are true or not, while an argument is sound if its conclusion follows from premises that are true. Propositional logic uses premises that are propositions, which are declarations that are either true or false, while predicate logic uses more complex premises called formulae that contain variables. These can be assigned values or can be quantified as to when they apply with the universal quantifier (always apply) or the existential quantifier (applies at least once). Inductive reasoning makes conclusions or generalizations based on probabilistic reasoning. For example, if “90% of humans are right-handed” and “Joe is human” then “Joe is probably right-handed”. Fields in logic include mathematical logic (formal symbolic logic) and philosophical logic.
Metaphysics is the study of the most general features of reality, such as existence, time, the relationship between mind and body, objects and their properties, wholes and their parts, events, processes, and causation. Traditional branches of metaphysics include cosmology, the study of the world in its entirety, and ontology, the study of being.
Within metaphysics itself there are a wide range of differing philosophical 
In addition to the aforementioned views, however, there is also an ontological dichotomy within metaphysics between the concepts of particulars and universals as well. Particulars are those objects that are said to exist in space and time, as opposed to abstract objects, such as numbers. Universals are properties held by multiple particulars, such as redness or a gender. The type of existence, if any, of universals and abstract objects is an issue of serious debate within metaphysical philosophy. Realism is the philosophical position that universals do in fact exist, while nominalism is the negation, or denial of universals, abstract objects, or both. Conceptualism holds that universals exist, but only within the mind's perception.
The question of whether or not existence is a predicate has been discussed since the Early Modern period. Essence is the set of attributes that make an object what it fundamentally is and without which it loses its identity. Essence is contrasted with accident: a property that the substance has contingently, without which the substance can still retain its identity.
Ethics and political philosophy
Ethics, or "moral philosophy," is concerned primarily with the question of the best way to live, and secondarily, concerning the question of whether this question can be answered. The main branches of ethics are meta-ethics, normative ethics, and applied ethics. Meta-ethics concerns the nature of ethical thought, such as the origins of the words good and bad, and origins of other comparative words of various ethical systems, whether there are absolute ethical truths, and how such truths could be known. Normative ethics are more concerned with the questions of how one ought to act, and what the right course of action is. This is where most ethical theories are generated. Lastly, applied ethics go beyond theory and step into real world ethical practice, such as questions of whether or not abortion is correct. Ethics is also associated with the idea of morality, and the two are often interchangeable.
One debate that has commanded the attention of ethicists in the modern era has been between consequentialism (actions are to be morally evaluated solely by their consequences) and deontology (actions are to be morally evaluated solely by consideration of agents' duties, the rights of those whom the action concerns, or both). Jeremy Bentham and John Stuart Mill are famous for propagating utilitarianism, which is the idea that the fundamental moral rule is to strive toward the "greatest happiness for the greatest number". However, in promoting this idea they also necessarily promoted the broader doctrine of consequentialism. Adopting a position opposed to consequentialism, Immanuel Kant argued that moral principles were simply products of reason. Kant believed that the incorporation of consequences into moral deliberation was a deep mistake, since it denies the necessity of practical maxims in governing the working of the will. According to Kant, reason requires that we conform our actions to the categorical imperative, which is an absolute duty. An important 20th-century deontologist, W.D. Ross, argued for weaker forms of duties called prima facie duties.
More recent works have emphasized the role of character in ethics, a movement known as the aretaic turn (that is, the turn towards virtues). One strain of this movement followed the work of Bernard Williams. Williams noted that rigid forms of consequentialism and deontology demanded that people behave impartially. This, Williams argued, requires that people abandon their personal projects, and hence their personal integrity, in order to be considered moral. G.E.M. Anscombe, in an influential paper, "Modern Moral Philosophy" (1958), revived virtue ethics as an alternative to what was seen as the entrenched positions of Kantianism and consequentialism. Aretaic perspectives have been inspired in part by research of ancient conceptions of virtue. For example, Aristotle's ethics demands that people follow the Aristotelian mean, or balance between two vices; and Confucian ethics argues that virtue consists largely in striving for harmony with other people. Virtue ethics in general has since gained many adherents, and has been defended by such philosophers as Philippa Foot, Alasdair MacIntyre, and Rosalind Hursthouse.
Political philosophy is the study of government and the relationship of individuals (or families and clans) to communities including the state. It includes questions about justice, law, property, and the rights and obligations of the citizen. Politics and ethics are traditionally inter-linked subjects, as both discuss the question of what is good and how people should live. From ancient times, and well beyond them, the roots of justification for political authority were inescapably tied to outlooks on human nature. In The Republic, Plato presented the argument that the ideal society would be run by a council of philosopher-kings, since those best at philosophy are best able to realize the good. Even Plato, however, required philosophers to make their way in the world for many years before beginning their rule at the age of fifty.
For Aristotle, humans are political animals (i.e. social animals), and governments are set up to pursue good for the community. Aristotle reasoned that, since the state (polis) was the highest form of community, it has the purpose of pursuing the highest good. Aristotle viewed political power as the result of natural inequalities in skill and virtue. Because of these differences, he favored an aristocracy of the able and virtuous. For Aristotle, the person cannot be complete unless he or she lives in a community. His The Nicomachean Ethics and The Politics are meant to be read in that order. The first book addresses virtues (or "excellences") in the person as a citizen; the second addresses the proper form of government to ensure that citizens will be virtuous, and therefore complete. Both books deal with the essential role of justice in civic life.
Later, Niccolò Machiavelli rejected the views of Aristotle and Thomas Aquinas as unrealistic. The ideal sovereign is not the embodiment of the moral virtues; rather the sovereign does whatever is successful and necessary, rather than what is morally praiseworthy. Thomas Hobbes also contested many elements of Aristotle's views. For Hobbes, human nature is essentially anti-social: people are essentially egoistic, and this egoism makes life difficult in the natural state of things. Moreover, Hobbes argued, though people may have natural inequalities, these are trivial, since no particular talents or virtues that people may have will make them safe from harm inflicted by others. For these reasons, Hobbes concluded that the state arises from a common agreement to raise the community out of the state of nature. This can only be done by the establishment of a sovereign, in which (or whom) is vested complete control over the community, and is able to inspire awe and terror in its subjects.
Many in the Enlightenment were unsatisfied with existing doctrines in political philosophy, which seemed to marginalize or neglect the possibility of a democratic state. Jean-Jacques Rousseau was among those who attempted to overturn these doctrines: he responded to Hobbes by claiming that a human is by nature a kind of "noble savage", and that society and social contracts corrupt this nature. Another critic was John Locke. In Second Treatise on Government he agreed with Hobbes that the nation-state was an efficient tool for raising humanity out of a deplorable state, but he argued that the sovereign might become an abominable institution compared to the relatively benign unmodulated state of nature.
Following the doctrine of the fact-value distinction, due in part to the influence of David Hume and his student Adam Smith, appeals to human nature for political justification were weakened. Nevertheless, many political philosophers, especially moral realists, still make use of some essential human nature as a basis for their arguments.
Marxism is derived from the work of Karl Marx and Friedrich Engels. Their idea that capitalism is based on exploitation of workers and causes alienation of people from their human nature, the historical materialism, their view of social classes, etc., have influenced many fields of study, such as sociology, economics, and politics. Marxism inspired the Marxist school of communism, which brought a huge impact on the history of the 20th century.
- Philosophy of language explores the nature, the origins, and the use of language.
- Philosophy of law (often called jurisprudence) explores the varying theories explaining the nature and the interpretations of law.
- Philosophy of mind explores the nature of the mind, and its relationship to the body, and is typified by disputes between dualism and materialism. In recent years there has been increasing similarity between this branch of philosophy and cognitive science.
- Philosophy of religion explores the questions regarding religion, including the nature and existence of God, the examination of religious experiences, analysis of religious vocabulary and texts, and the relationship of religion and science.
- Philosophy of science explores the foundations, methods, implications, and purpose of science.
- Metaphilosophy explores the aims of philosophy, its boundaries, and its methods.
Many societies have considered philosophical questions and built philosophical traditions based upon each other's works.
Egypt and Babylon
There are authors who date the philosophical maxims of Ptahhotep before the 25th century. For instance, Pulitzer Prize–winning historian Will Durant dates these writings as early as 2880 BCE within The Story of Civilization: Our Oriental History. Durant claims that Ptahhotep could be considered the very first philosopher in virtue of having the earliest and surviving fragments of moral philosophy (i.e., "The Maxims of Ptah-Hotep"). Ptahhotep's grandson, Ptahhotep Tshefi, is traditionally credited with being the author of the collection of wise sayings known as The Maxims of Ptahhotep, whose opening lines attribute authorship to the vizier Ptahhotep: Instruction of the Mayor of the city, the Vizier Ptahhotep, under the Majesty of King Isesi.
The origins of Babylonian philosophy can be traced back to the wisdom of early Mesopotamia, which embodied certain philosophies of life, particularly ethics, in the forms of dialectic, dialogues, epic poetry, folklore, hymns, lyrics, prose, and proverbs. The reasoning and rationality of the Babylonians developed beyond empirical observation. The Babylonian text Dialog of Pessimism contains similarities to the agnostic thought of the sophists, the Heraclitean doctrine of contrasts, and the dialogues of Plato, as well as a precursor to the maieutic Socratic method of Socrates and Plato. The Milesian philosopher Thales is also traditionally said to have studied philosophy in Mesopotamia.
Philosophy has had a tremendous effect on Chinese civilization, and throughout East Asia. The majority of Chinese philosophy originates in the Spring and Autumn and Warring States era, during a period known as the "Hundred Schools of Thought", which was characterized by significant intellectual and cultural developments. It was during this era that the major philosophies of China, Confucianism, Mohism, Legalism, and Taoism, arose, along with philosophies that later fell into obscurity, like Agriculturalism, Chinese Naturalism, and the Logicians. Of the many philosophical schools of China, only Confucianism and Taoism existed after the Qin Dynasty suppressed any Chinese philosophy that was opposed to Legalism.
Confucianism is humanistic, philosophy that believes that human beings are teachable, improvable and perfectible through personal and communal endeavour especially including self-cultivation and self-creation. Confucianism focuses on the cultivation of virtue and maintenance of ethics, the most basic of which are ren, yi, and li. Ren is an obligation of altruism and humaneness for other individuals within a community, yi is the upholding of righteousness and the moral disposition to do good, and li is a system of norms and propriety that determines how a person should properly act within a community.
Taoism focuses on establishing harmony with the Tao, which is origin of and the totality of everything that exists. The word "Tao" (or "Dao", depending on the romanization scheme) is usually translated as "way", "path" or "principle". Taoist propriety and ethics emphasize the Three Jewels of the Tao: compassion, moderation, and humility, while Taoist thought generally focuses on nature, the relationship between humanity and the cosmos (天人相应); health and longevity; and wu wei, action through inaction. Harmony with the Universe, or the origin of it through the Tao, is the intended result of many Taoist rules and practices.
Ancient Graeco-Roman philosophy is a period of Western philosophy, starting in the 6th century [c. 585] BC to the 6th century AD. It is usually divided into three periods: the pre-Socratic period, the Ancient Classical Greek period of Plato and Aristotle, and the post-Aristotelian (or Hellenistic) period. A fourth period that is sometimes added includes the Neoplatonic and Christian philosophers of Late Antiquity. The most important of the ancient philosophers (in terms of subsequent influence) are Plato and Aristotle. Plato specifically, is credited as the founder of Western philosophy. The philosopher Alfred North Whitehead said of Plato: "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato. I do not mean the systematic scheme of thought which scholars have doubtfully extracted from his writings. I allude to the wealth of general ideas scattered through them."
It was said in Roman Ancient history that Pythagoras was the first man to call himself a philosopher, or lover of wisdom, and Pythagorean ideas exercised a marked influence on Plato, and through him, all of Western philosophy. Plato and Aristotle, the first Classical Greek philosophers, did refer critically to other simple "wise men", which were called in Greek "sophists," and which were common before Pythagoras' time. From their critique it appears that a distinction was then established in their own Classical period between the more elevated and pure "lovers of wisdom" (the true Philosophers), and these other earlier and more common traveling teachers, who often also earned money from their craft.
The main subjects of ancient philosophy are: understanding the fundamental causes and principles of the universe; explaining it in an economical way; the epistemological problem of reconciling the diversity and change of the natural universe, with the possibility of obtaining fixed and certain knowledge about it; questions about things that cannot be perceived by the senses, such as numbers, elements, universals, and gods. Socrates is said to have been the initiator of more focused study upon the human things including the analysis of patterns of reasoning and argument and the nature of the good life and the importance of understanding and knowledge in order to pursue it; the explication of the concept of justice, and its relation to various political systems.
In this period the crucial features of the Western philosophical method were established: a critical approach to received or established views, and the appeal to reason and argumentation. This includes Socrates' dialectic method of inquiry, known as the Socratic method or method of "elenchus", which he largely applied to the examination of key moral concepts such as the Good and Justice. To solve a problem, it would be broken down into a series of questions, the answers to which gradually distill the answer a person would seek. The influence of this approach is most strongly felt today in the use of the scientific method, in which hypothesis is the first stage.
The term Indian philosophy (Sanskrit: Darshanas), refers to any of several schools of philosophical thought that originated in the Indian subcontinent, including Hindu philosophy, Buddhist philosophy, and Jain philosophy. Having the same or rather intertwined origins, all of these philosophies have a common underlying themes of Dharma and Karma, and similarly attempt to explain the attainment of emancipation. They have been formalized and promulgated chiefly between 1000 BC to a few centuries AD.
India's philosophical tradition dates back to the composition of the Upanisads in the later Vedic period (c. 1000-500 BCE). Subsequent schools (Skt: Darshanas) of Indian philosophy were identified as orthodox (Skt: astika) or non-orthodox (Skt: nastika), depending on whether or not they regarded the Vedas as an infallible source of knowledge. By some classifications, there are six schools of orthodox Hindu philosophy and three heterodox schools. The orthodox are Nyaya, Vaisesika, Samkhya, Yoga, Purva mimamsa and Vedanta. The Heterodox are Jain, Buddhist and materialist (Cārvāka). Other classifications also include Pashupata, Saiva, Raseśvara and Pāṇini Darśana with the other orthodox schools.
Competition and integration between the various schools was intense during their formative years, especially between 500 BC to 200 AD. Some like the Jain, Buddhist, Shaiva and Vedanta schools survived, while others like Samkhya and Ajivika did not, either being assimilated or going extinct. The Sanskrit term for "philosopher" is dārśanika, one who is familiar with the systems of philosophy, or darśanas.
In the history of the Indian subcontinent, following the establishment of a Vedic culture, the development of philosophical and religious thought over a period of two millennia gave rise to what came to be called the six schools of astika, or orthodox, Indian or Hindu philosophy. These schools have come to be synonymous with the greater religion of Hinduism, which was a development of the early Vedic religion.
Persian philosophy can be traced back as far as Old Iranian philosophical traditions and thoughts, with their ancient Indo-Iranian roots. These were considerably influenced by Zarathustra's teachings. Throughout Iranian history and due to remarkable political and social influences such as the Macedonian, the Arab, and the Mongol invasions of Persia, a wide spectrum of schools of thought arose. These espoused a variety of views on philosophical questions, extending from Old Iranian and mainly Zoroastrianism-influenced traditions to schools appearing in the late pre-Islamic era, such as Manicheism and Mazdakism, as well as various post-Islamic schools. Iranian philosophy after Arab invasion of Persia is characterized by different interactions with the old Iranian philosophy, the Greek philosophy and with the development of Islamic philosophy. Illuminationism and the transcendent theosophy are regarded as two of the main philosophical traditions of that era in Persia. Zoroastrianism has been identified as one of the key early events in the development of philosophy.
Medieval philosophy is the philosophy of Western Europe and the Middle East during the Middle Ages, roughly extending from the Christianization of the Roman Empire until the Renaissance. Medieval philosophy is defined partly by the rediscovery and further development of classical Greek and Hellenistic philosophy, and partly by the need to address theological problems and to integrate the then widespread sacred doctrines of Abrahamic religion (Islam, Judaism, and Christianity) with secular learning.
The history of western European medieval philosophy is traditionally divided into two main periods: the period in the Latin West following the Early Middle Ages until the 12th century, when the works of Aristotle and Plato were preserved and cultivated; and the "golden age" of the 12th, 13th and 14th centuries in the Latin West, which witnessed the culmination of the recovery of ancient philosophy, and significant developments in the field of philosophy of religion, logic and metaphysics.
The medieval era was disparagingly treated by the Renaissance humanists, who saw it as a barbaric "middle" period between the classical age of Greek and Roman culture, and the "rebirth" or renaissance of classical culture. Yet this period of nearly a thousand years was the longest period of philosophical development in Europe, and possibly the richest. 
Some problems discussed throughout this period are the relation of faith to reason, the existence and unity of God, the object of theology and metaphysics, the problems of knowledge, of universals, and of individuation.
Philosophers from the Middle Ages include the Christian philosophers Augustine of Hippo, Boethius, Anselm, Gilbert of Poitiers, Peter Abelard, Roger Bacon, Bonaventure, Thomas Aquinas, Duns Scotus, William of Ockham and Jean Buridan; the Jewish philosophers Maimonides and Gersonides; and the Muslim philosophers Alkindus, Alfarabi, Alhazen, Avicenna, Algazel, Avempace, Abubacer, Ibn Khaldūn, and Averroes. The medieval tradition of Scholasticism continued to flourish as late as the 17th century, in figures such as Francisco Suarez and John of St. Thomas.
Aquinas, father of Thomism, was immensely influential in Catholic Europe, placed a great emphasis on reason and argumentation, and was one of the first to use the new translation of Aristotle's metaphysical and epistemological writing. His work was a significant departure from the Neoplatonic and Augustinian thinking that had dominated much of early Scholasticism.
The Renaissance ("rebirth") was a period of transition between the Middle Ages and modern thought, in which the recovery of classical texts helped shift philosophical interests away from technical studies in logic, metaphysics, and theology towards eclectic inquiries into morality, philology, and mysticism. The study of the classics and the humane arts generally, such as history and literature, enjoyed a scholarly interest hitherto unknown in Christendom, a tendency referred to as humanism. Displacing the medieval interest in metaphysics and logic, the humanists followed Petrarch in making man and his virtues the focus of philosophy.
The study of classical philosophy also developed in two new ways. On the one hand, the study of Aristotle was changed through the influence of Averroism. The disagreements between these Averroist Aristotelians, and more orthodox catholic Aristotelians such as Albertus Magnus and Thomas Aquinas eventually contributed to the development of a "humanist Aristotelianism" developed in the Renaissance, as exemplified in the thought of Pietro Pomponazzi and Giacomo Zabarella. Secondly, as an alternative to Aristotle, the study of Plato and the Neoplatonists became common. This was assisted by the rediscovery of works which had not been well known previously in Western Europe. Notable Renaissance Platonists include Nicholas of Cusa, and later Marsilio Ficino and Giovanni Pico della Mirandola.
The Renaissance also renewed interest in anti-Aristotelian theories of nature considered as an organic, living whole comprehensible independently of theology, as in the work of Nicholas of Cusa, Nicholas Copernicus, Giordano Bruno, Telesius, and Tommaso Campanella. Such movements in natural philosophy dovetailed with a revival of interest in occultism, magic, hermeticism, and astrology, which were thought to yield hidden ways of knowing and mastering nature (e.g., in Marsilio Ficino and Giovanni Pico della Mirandola).
These new movements in philosophy developed contemporaneously with larger religious and political transformations in Europe: the Reformation and the decline of feudalism. Though the theologians of the Protestant Reformation showed little direct interest in philosophy, their destruction of the traditional foundations of theological and intellectual authority harmonized with a revival of fideism and skepticism in thinkers such as Erasmus, Montaigne, and Francisco Sanches. Meanwhile, the gradual centralization of political power in nation-states was echoed by the emergence of secular political philosophies, as in the works of Niccolò Machiavelli (often described as the first modern political thinker, or a key turning point towards modern political thinking), Thomas More, Erasmus, Justus Lipsius, Jean Bodin, and Hugo Grotius.
Mid-Imperial Chinese philosophy is primarily defined by the development of Neo-Confucianism. During the Tang Dynasty, Buddhism from Nepal also became a prominent philosophical and religious discipline. (It should be noted that philosophy and religion were clearly distinguished in the West, whilst these concepts were more continuous in the East due to, for example, the philosophical concepts of Buddhism.)
Neo-Confucianism is a philosophical movement that advocated a more rationalist and secular form of Confucianism by rejecting superstitious and mystical elements of Daoism and Buddhism that had influenced Confucianism during and after the Han Dynasty. Although the Neo-Confucianists were critical of Daoism and Buddhism, the two did have an influence on the philosophy, and the Neo-Confucianists borrowed terms and concepts from both. However, unlike the Buddhists and Daoists, who saw metaphysics as a catalyst for spiritual development, religious enlightenment, and immortality, the Neo-Confucianists used metaphysics as a guide for developing a rationalist ethical philosophy.
Neo-Confucianism has its origins in the Tang Dynasty; the Confucianist scholars Han Yu and Li Ao are seen as forbears of the Neo-Confucianists of the Song Dynasty. The Song Dynasty philosopher Zhou Dunyi is seen as the first true "pioneer" of Neo-Confucianism, using Daoist metaphysics as a framework for his ethical philosophy.
Elsewhere in East Asia, Japanese Philosophy began to develop as indigenous Shinto beliefs fused with Buddhism, Confucianism and other schools of Chinese philosophy and Indian philosophy. Similar to Japan, in Korean philosophy the emotional content of Shamanism was integrated into the Neo-Confucianism imported from China.
The period between 5th and 9th centuries CE was the most brilliant epoch in the development of Indian philosophy as Hindu and Buddhist philosophies flourished side by side. Of these various schools of thought the non-dualistic Advaita Vedanta emerged as the most influential and most dominant school of philosophy. The major philosophers of this school were Gaudapada, Adi Shankara and Vidyaranya.
Advaita Vedanta rejects theism and dualism by insisting that “Brahman [ultimate reality] is without parts or attributes...one without a second.” Since Brahman has no properties, contains no internal diversity and is identical with the whole reality, it cannot be understood as God. Brahman though being indescribable is at best described as Satchidananda (merging "Sat" + "Chit" + "Ananda", i.e., Existence, Consciousness and Bliss) by Shankara. Advaita ushered a new era in Indian philosophy and as a result, many new schools of thought arose in the medieval period. Some of them were Visishtadvaita (qualified monism), Dvaita (dualism), Dvaitadvaita (dualism-nondualism), Suddhadvaita (pure non-dualism), Achintya Bheda Abheda and Pratyabhijña (the recognitive school).
In early Islamic thought, which refers to philosophy during the "Islamic Golden Age", traditionally dated between the 8th and 12th centuries, two main currents may be distinguished. The first is Kalam, that mainly dealt with Islamic theological questions. These include the Mu'tazili and Ash'ari. The other is Falsafa, that was founded on interpretations of Aristotelianism and Neoplatonism. There were attempts by later philosopher-theologians at harmonizing both trends, notably by Ibn Sina (Avicenna) who founded the school of Avicennism, Ibn Rushd (Averroës) who founded the school of Averroism, and others such as Ibn al-Haytham (Alhacen) and Abū Rayhān al-Bīrūnī.
Early modern philosophy
Chronologically, the early modern era of Western philosophy is usually identified with the 17th and 18th centuries, with the 18th century often being referred to as the Enlightenment. Modern philosophy is distinguished from its predecessors by its increasing independence from traditional authorities such as the Church, academia, and Aristotelianism; a new focus on the foundations of knowledge and metaphysical system-building; and the emergence of modern physics out of natural philosophy.
Other central topics of philosophy in this period include the nature of the mind and its relation to the body, the implications of the new natural sciences for traditional theological topics such as free will and God, and the emergence of a secular basis for moral and political philosophy. These trends first distinctively coalesce in Francis Bacon's call for a new, empirical program for expanding knowledge, and soon found massively influential form in the mechanical physics and rationalist metaphysics of René Descartes.
Berkeley, Hume, and Kant, though influential contributions to philosophy were made by many thinkers in this period, such as Galileo Galilei, Pierre Gassendi, Blaise Pascal, Nicolas Malebranche, Isaac Newton, Christian Wolff, Montesquieu, Pierre Bayle, Thomas Reid, Jean d'Alembert, and Adam Smith. Jean-Jacques Rousseau was a seminal figure in initiating reaction against the Enlightenment. The approximate end of the early modern period is most often identified with Immanuel Kant's systematic attempt to limit metaphysics, justify scientific knowledge, and reconcile both of these with morality and freedom.
Later modern philosophy is usually considered to begin after the philosophy of Friedrich Wilhelm Joseph Schelling, transformed the work of Kant by maintaining that the world is constituted by a rational or mind-like process, and as such is entirely knowable. Arthur Schopenhauer's identification of this world-constituting process as an irrational will to live influenced later 19th- and early 20th-century thinking, such as the work of Friedrich Nietzsche and Sigmund Freud.
After Hegel's death in 1831, 19th-century philosophy largely turned against idealism in favor of varieties of philosophical Gottlob Frege. Other philosophers who initiated lines of thought that would continue to shape philosophy into the 20th century include:
- Gottlob Frege and Henry Sidgwick, whose work in logic and ethics, respectively, provided the tools for early analytic philosophy.
- Charles Sanders Peirce and William James, who founded pragmatism.
- Søren Kierkegaard and Friedrich Nietzsche, who laid the groundwork for existentialism and post-structuralism.
Within the last century, philosophy has increasingly become a professional discipline practiced within universities, like other academic disciplines. Accordingly, it has become less general and more specialized. In the view of one prominent recent historian: "Philosophy has become a highly organized discipline, done by specialists primarily for other specialists. The number of philosophers has exploded, the volume of publication has swelled, and the subfields of serious philosophical investigation have multiplied. Not only is the broad field of philosophy today far too vast to be embraced by one mind, something similar is true even of many highly specialized subfields."
In the English-speaking world, analytic philosophy became the dominant school for much of the 20th century. In the first half of the century, it was a cohesive school, shaped strongly by logical positivism, united by the notion that philosophical problems could and should be solved by attention to logic and language. The pioneering work of Bertrand Russell was a model for the early development of analytic philosophy, moving from a rejection of the idealism dominant in late 19th-century British philosophy to an neo-Humean empiricism, strengthened by the conceptual resources of modern mathematical logic.
In the latter half of the 20th century, analytic philosophy diffused into a wide variety of disparate philosophical views, only loosely united by historical lines of influence and a self-identified commitment to clarity and rigor. The post-war transformation of the analytic program led in two broad directions: on one hand, an interest in ordinary language as a way of avoiding or redescribing traditional philosophical problems, and on the other, a more thoroughgoing naturalism that sought to dissolve the puzzles of modern philosophy via the results of the natural sciences (such as cognitive psychology and evolutionary biology). The shift in the work of Ludwig Wittgenstein, from a view congruent with logical positivism to a therapeutic dissolution of traditional philosophy as a linguistic misunderstanding of normal forms of life, was the most influential version of the first direction in analytic philosophy. The later work of Russell and the philosophy of W.V.O. Quine are influential exemplars of the naturalist approach dominant in the second half of the 20th century. But the diversity of analytic philosophy from the 1970s onward defies easy generalization: the naturalism of Quine and his epigoni was in some precincts superseded by a "new metaphysics" of possible worlds, as in the influential work of David Lewis. Recently, the experimental philosophy movement has sought to reappraise philosophical problems through social science research techniques.
On continental Europe, no single school or temperament enjoyed dominance. The flight of the logical positivists from central Europe during the 1930s and 1940s, however, diminished philosophical interest in natural science, and an emphasis on the humanities, broadly construed, figures prominently in what is usually called "continental philosophy". 20th-century movements such as phenomenology, existentialism, modern hermeneutics, critical theory, structuralism, and poststructuralism are included within this loose category. The founder of phenomenology, Edmund Husserl, sought to study consciousness as experienced from a first-person perspective, while Martin Heidegger drew on the ideas of Kierkegaard, Nietzsche, and Husserl to propose an unconventional existential approach to ontology.
In the Arab-speaking world Arab nationalist philosophy became the dominant school of thought, involving philosophers such as Michel Aflaq, Zaki al-Arsuzi, Salah al-Din al-Bitar of ba'athism and Sati' al-Husri. These people disregarded much of Marx's research, and were mostly concerned with the individual's spirituality which would, in the fight against imperialism and oppression, lead to a united Arab Nation.
Forms of idealism were prevalent in philosophy from the 18th century to the early 20th century. Transcendental idealism, advocated by Immanuel Kant, is the view that there are limits on what can be understood, since there is much that cannot be brought under the conditions of objective judgment. Kant wrote his Critique of Pure Reason (1781–1787) in an attempt to reconcile the conflicting approaches of rationalism and empiricism, and to establish a new groundwork for studying metaphysics. Kant's intention with this work was to look at what we know and then consider what must be true about it, as a logical consequence of the way we know it. One major theme was that there are fundamental features of reality that escape our direct knowledge because of the natural limits of the human faculties. Although Kant held that objective knowledge of the world required the mind to impose a conceptual or categorical framework on the stream of pure sensory data—a framework including space and time themselves—he maintained that things-in-themselves existed independently of our perceptions and judgments; he was therefore not an idealist in any simple sense. Kant's account of things-in-themselves is both controversial and highly complex. Continuing his work, Johann Gottlieb Fichte and Friedrich Schelling dispensed with belief in the independent existence of the world, and created a thoroughgoing idealist philosophy.
The most notable work of this G. W. F. Hegel's Phenomenology of Spirit, of 1807. Hegel admitted his ideas were not new, but that all the previous philosophies had been incomplete. His goal was to correctly finish their job. Hegel asserts that the twin aims of philosophy are to account for the contradictions apparent in human experience (which arise, for instance, out of the supposed contradictions between "being" and "not being"), and also simultaneously to resolve and preserve these contradictions by showing their compatibility at a higher level of examination ("being" and "not being" are resolved with "becoming"). This program of acceptance and reconciliation of contradictions is known as the "Hegelian dialectic". Philosophers influenced by Hegel include Ludwig Andreas Feuerbach, who coined the term projection as pertaining to our inability to recognize anything in the external world without projecting qualities of ourselves upon those things; Karl Marx; Friedrich Engels; and the British idealists, notably T. H. Green, J. M. E. McTaggart and F. H. Bradley.
Few 20th-century philosophers have embraced idealism. However, quite a few have embraced Hegelian dialectic. Immanuel Kant's "Copernican Turn" also remains an important philosophical concept today.
Pragmatism was founded in the spirit of finding a scientific concept of truth that does not depend on personal insight (revelation) or reference to some metaphysical realm. The meaning or purport of a statement should be judged by the effect its acceptance would have on practice. Truth is that opinion which inquiry taken far enough would ultimately reach. For Charles Sanders Peirce these were principles of the inquirer's self-regulation, implied by the idea and hope that inquiry is not generally fruitless. The details of how these principles should be interpreted have been subject to discussion since Peirce first conceived them. Peirce's maxim of pragmatism is as follows: "Consider what effects, which might conceivably have practical bearings, we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object." Like postmodern neo-pragmatist Richard Rorty, many are convinced that pragmatism asserts that the truth of beliefs does not consist in their correspondence with reality, but in their usefulness and efficacy.
Edmund Husserl's phenomenology was an ambitious attempt to lay the foundations for an account of the structure of conscious experience in general. An important part of Husserl's phenomenological project was to show that all conscious acts are directed at or about objective content, a feature that Husserl called intentionality.
In the first part of his two-volume work, the Logical Investigations (1901), he launched an extended attack on psychologism. In the second part, he began to develop the technique of descriptive phenomenology, with the aim of showing how objective judgments are grounded in conscious experience—not, however, in the first-person experience of particular individuals, but in the properties essential to any experiences of the kind in question.
He also attempted to identify the essential properties of any act of meaning. He developed the method further in Ideas (1913) as transcendental phenomenology, proposing to ground actual experience, and thus all fields of human knowledge, in the structure of consciousness of an ideal, or transcendental, ego. Later, he attempted to reconcile his transcendental standpoint with an acknowledgement of the intersubjective life-world in which real individual subjects interact. Husserl published only a few works in his lifetime, which treat phenomenology mainly in abstract methodological terms; but he left an enormous quantity of unpublished concrete analyses.
Husserl's work was immediately influential in Germany, with the foundation of phenomenological schools in Munich and Göttingen. Phenomenology later achieved international fame through the work of such philosophers as Martin Heidegger (formerly Husserl's research assistant), Maurice Merleau-Ponty, and Jean-Paul Sartre. Through the work of Heidegger and Sartre, Husserl's focus on subjective experience influenced aspects of existentialism.
Existentialism is a term applied to the work of a number of late 19th- and 20th-century philosophers who, despite profound doctrinal differences, shared the belief that philosophical thinking begins with the human subject—not merely the thinking subject, but the acting, feeling, living human individual. In existentialism, the individual's starting point is characterized by what has been called "the existential attitude", or a sense of disorientation and confusion in the face of an apparently meaningless or absurd world. Many existentialists have also regarded traditional systematic or academic philosophy, in both style and content, as too abstract and remote from concrete human experience.
Although they did not use the term, the 19th-century philosophers Søren Kierkegaard and Friedrich Nietzsche are widely regarded as the fathers of existentialism. Their influence, however, has extended beyond existentialist thought.
The main target of Kierkegaard's writings was the idealist philosophical system of Hegel which, he thought, ignored or excluded the inner subjective life of living human beings. Kierkegaard, conversely, held that "truth is subjectivity", arguing that what is most important to an actual human being are questions dealing with an individual's inner relationship to existence. In particular, Kierkegaard, a Christian, believed that the truth of religious faith was a subjective question, and one to be wrestled with passionately.
Although Kierkegaard and Nietzsche were among his influences, the extent to which the German philosopher Martin Heidegger should be considered an existentialist is debatable. In Being and Time he presented a method of rooting philosophical explanations in human existence (Dasein) to be analysed in terms of existential categories (existentiale); and this has led many commentators to treat him as an important figure in the existentialist movement. However, in The Letter on Humanism, Heidegger explicitly rejected the existentialism of Jean-Paul Sartre.
Sartre became the best-known proponent of existentialism, exploring it not only in theoretical works such as Being and Nothingness, but also in plays and novels. Sartre, along with Simone de Beauvoir, represented an avowedly atheistic branch of existentialism, which is now more closely associated with their ideas of nausea, contingency, bad faith, and the absurd than with Kierkegaard's spiritual angst. Nevertheless, the focus on the individual human being, responsible before the universe for the authenticity of his or her existence, is common to all these thinkers.
Structuralism and post-structuralism
Inaugurated by the linguist Ferdinand de Saussure, structuralism sought to clarify systems of signs through analyzing the discourses they both limit and make possible. Saussure conceived of the sign as being delimited by all the other signs in the system, and ideas as being incapable of existence prior to linguistic structure, which articulates thought. This led continental thought away from humanism, and toward what was termed the decentering of man: language is no longer spoken by man to express a true inner self, but language speaks man.
Structuralism sought the province of a hard science, but its positivism soon came under fire by poststructuralism, a wide field of thinkers, some of whom were once themselves structuralists, but later came to criticize it. Structuralists believed they could analyze systems from an external, objective standing, for example, but the poststructuralists argued that this is incorrect, that one cannot transcend structures and thus analysis is itself determined by what it examines, while the distinction between the signifier and signified was treated as crystalline by structuralists, poststructuralists asserted that every attempt to grasp the signified results in more signifiers, so meaning is always in a state of being deferred, making an ultimate interpretation impossible.
Structuralism came to dominate continental philosophy throughout the 1960s and early 1970s, encompassing thinkers as diverse as Claude Lévi-Strauss, Roland Barthes and Jacques Lacan. Post-structuralism came to predominate over the 1970s onwards, including thinkers such as Michel Foucault, Jacques Derrida, Gilles Deleuze and even Roland Barthes; it incorporated a critique of structuralism's limitations.
The analytic tradition
The term analytic philosophy roughly designates a group of philosophical methods that stress detailed argumentation, attention to semantics, use of classical logic and non-classical logics and clarity of meaning above all other criteria. Some have held that philosophical problems arise through misuse of language or because of misunderstandings of the logic of our language, while some maintain that there are genuine philosophical problems and that philosophy is continuous with science. Michael Dummett in his Origins of Analytical Philosophy makes the case for counting Gottlob Frege's The Foundations of Arithmetic as the first analytic work, on the grounds that in that book Frege took the linguistic turn, analyzing philosophical problems through language. Bertrand Russell and G.E. Moore are also often counted as founders of analytic philosophy, beginning with their rejection of British idealism, their defense of realism and the emphasis they laid on the legitimacy of analysis. Russell's classic works The Principles of Mathematics, On Denoting and Principia Mathematica with Alfred North Whitehead, aside from greatly promoting the use of mathematical logic in philosophy, set the ground for much of the research program in the early stages of the analytic tradition, emphasizing such problems as: the reference of proper names, whether 'existence' is a property, the nature of propositions, the analysis of definite descriptions, the discussions on the foundations of mathematics; as well as exploring issues of ontological commitment and even metaphysical problems regarding time, the nature of matter, mind, persistence and change, which Russell tackled often with the aid of mathematical logic. Russell and Moore's philosophy, in the beginning of the 20th century, developed as a critique of Hegel and his British followers in particular, and of grand systems of speculative philosophy in general, though by no means all analytic philosophers reject the philosophy of Hegel (see Charles Taylor) nor speculative philosophy. Some schools in the group include logical positivism, and ordinary language both markedly influenced by Russell and Wittgenstein's development of Logical Atomism the former positively and the latter negatively.
In 1921, Ludwig Wittgenstein, who studied under Russell at Cambridge, published his Tractatus Logico-Philosophicus, which gave a rigidly "logical" account of linguistic and philosophical issues. At the time, he understood most of the problems of philosophy as mere puzzles of language, which could be solved by investigating and then minding the logical structure of language. Years later, he reversed a number of the positions he set out in the Tractatus, in for example his second major work, Philosophical Investigations (1953). Investigations was influential in the development of "ordinary language philosophy," which was promoted by Gilbert Ryle, J.L. Austin, and a few others. In the United States, meanwhile, the philosophy of W.V.O. Quine was having a major influence, with such classics as Two Dogmas of Empiricism. In that paper Quine criticizes the distinction between analytic and synthetic statements, arguing that a clear conception of analyticity is unattainable. He argued for holism, the thesis that language, including scientific language, is a set of interconnected sentences, none of which can be verified on its own, rather, the sentences in the language depend on each other for their meaning and truth conditions. A consequence of Quine's approach is that language as a whole has only a thin relation to experience. Some sentences that refer directly to experience might be modified by sense impressions, but as the whole of language is theory-laden, for the whole language to be modified, more than this is required. However, most of the linguistic structure can in principle be revised, even logic, in order to better model the world. Notable students of Quine include Donald Davidson and Daniel Dennett. The former devised a program for giving a semantics to natural language and thereby answer the philosophical conundrum "what is meaning?". A crucial part of the program was the use of Alfred Tarski's semantic theory of truth. Dummett, among others, argued that truth conditions should be dispensed within the theory of meaning, and replaced by assertibility conditions. Some propositions, on this view, are neither true nor false, and thus such a theory of meaning entails a rejection of the law of the excluded middle. This, for Dummett, entails antirealism, as Russell himself pointed out in his An Inquiry into Meaning and Truth.
By the 1970s there was a renewed interest in many traditional philosophical problems by the younger generations of analytic philosophers. David Lewis, Saul Kripke, Derek Parfit and others took an interest in traditional metaphysical problems, which they began exploring by the use of logic and philosophy of language. Among those problems some distinguished ones were: free will, essentialism, the nature of personal identity, identity over time, the nature of the mind, the nature of causal laws, space-time, the properties of material beings, modality, etc. In those universities where analytic philosophy has spread, these problems are still being discussed passionately. Analytic philosophers are also interested in the methodology of analytic philosophy itself, with Timothy Williamson, Wykeham Professor of Logic at Oxford, publishing recently a book entitled The Philosophy of Philosophy. Some influential figures in contemporary analytic philosophy are: Timothy Williamson, David Lewis, John Searle, Thomas Nagel, Hilary Putnam, Michael Dummett, Peter van Inwagen and Saul Kripke. Analytic philosophy has sometimes been accused of not contributing to the political debate or to traditional questions in aesthetics. However, with the appearance of A Theory of Justice by John Rawls and Anarchy, State and Utopia by Robert Nozick, analytic political philosophy acquired respectability. Analytic philosophers have also shown depth in their investigations of aesthetics, with Roger Scruton, Nelson Goodman, Arthur Danto and others developing the subject to its current shape.
The ideas conceived by a society have profound repercussions on what actions the society performs. The applied study of philosophy yields applications such as those in ethics—applied ethics in particular—and political philosophy. The political and economic philosophies of Confucius, Sun Zi, Chanakya, Ibn Khaldun, Ibn Rushd, Ibn Taimiyyah, Niccolò Machiavelli, Gottfried Wilhelm Leibniz, John Locke, Jean-Jacques Rousseau, Adam Smith, Karl Marx, John Stuart Mill, Leo Tolstoy, Mahatma Gandhi, Martin Luther King Jr., and others—all of these have been used to shape and justify governments and their actions.
In the field of philosophy of education, progressive education as championed by John Dewey has had a profound impact on educational practices in the United States in the 20th century. Descendants of this movement include the current efforts in philosophy for children, which are part of philosophy education. Carl von Clausewitz's political philosophy of war has had a profound effect on statecraft, international politics, and military strategy in the 20th century, especially in the years around World War II. Logic has become crucially important in mathematics, linguistics, psychology, computer science, and computer engineering.
Other important applications can be found in epistemology, which aid in understanding the requisites for knowledge, sound evidence, and justified belief (important in law, economics, decision theory, and a number of other disciplines). The philosophy of science discusses the underpinnings of the scientific method and has affected the nature of scientific investigation and argumentation. As such, philosophy has fundamental implications for science as a whole. For example, the strictly empirical approach of Skinner's behaviorism affected for decades the approach of the American psychological establishment. Deep ecology and animal rights examine the moral situation of humans as occupants of a world that has non-human occupants to consider also. Aesthetics can help to interpret discussions of music, literature, the plastic arts, and the whole artistic dimension of life. In general, the various philosophies strive to provide practical activities with a deeper understanding of the theoretical or conceptual underpinnings of their fields.
Often philosophy is seen as an investigation into an area not sufficiently well understood to be its own branch of knowledge. For example, what were once philosophical pursuits have evolved into the modern day fields such as psychology, sociology, linguistics, and economics.
- List of important publications in philosophy
- List of years in philosophy
- List of philosophers
- List of philosophy journals
- List of unsolved problems in philosophy
- Social theory
- Jenny Teichmann and Katherine C. Evans, Philosophy: A Beginner's Guide (Blackwell Publishing, 1999), p. 1: "Philosophy is a study of problems which are ultimate, abstract and very general. These problems are concerned with the nature of existence, knowledge, morality, reason and human purpose."
- "Philosophy". Mirriam-Webster on-line dictionary.
- φιλοσοφία. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
- "Online Etymology Dictionary". Etymonline.com. Retrieved 2010-08-22.
- The definition of philosophy is: "1. orig., love of, or the search for, wisdom or knowledge 2. theory or logical analysis of the principles underlying conduct, thought, knowledge, and the nature of the universe". Webster's New World Dictionary (Second College ed.).
- See Diogenes Laertius: "Lives of Eminent Philosophers", I, 12; Cicero: "Tusculanae disputationes", V, 8–9
- "Undergraduate Program | Department of Philosophy | NYU". Philosophy.fas.nyu.edu. Retrieved 2012-08-17.
- "Aesthetics- definition". Merriam-Webster Dictionary. Retrieved 2010-12-14.
- Descartes, René (1644). The Principles of Philosophy (IX).
- "Idealism". philosophybasics.com. Retrieved 2011-12-20.
Rodriguez-Pereyra, Gonzalo (2008). "Nominalism in Metaphysics", The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.). (link)
"The word 'Nominalism', as used by contemporary philosophers in the Anglo-American tradition, is ambiguous. In one sense, its most traditional sense deriving from the Middle Ages, it implies the rejection of universals. In another, more modern but equally entrenched sense, it implies the rejection of abstract objects"
- Strawson, P. F. "Conceptualism." Universals, concepts and qualities: new essays on the meaning of predicates. Ashgate Publishing, 2006.
- Hobbes, Thomas (1985). Leviathan. Penguin Classics.
- Sigmund, Paul E. (2005). The Selected Political Writings of John Locke. Norton.
- For example, the multi-author Oxford History of Western Philosophy breaks the subject into eight volumes: ancient, medieval, Renaissance, two volumes covering the period 1600–1750, two volumes covering 1750–1945, and one volume on analytic philosophy since 1945. Anthony Kenny's New History of Western Philosophy is divided in four volumes: ancient, medieval, early modern (1500–1830), and later modern (1830 to the present). The more technical Cambridge History of Philosophy divides the topic into nine periods: Greek philosophy to Aristotle, Hellenistic philosophy, later Greek and early medieval, later medieval, Renaissance, three volumes for the 17th–19th centuries, and a final volume on 1870–1945.
- "The Maxims of Good Discourse". Africanholocaust.net. Retrieved 2012-08-17.
- M. Lichtheim, Ancient Egyptian Literature, p.61
- Grimal, p.79
- Giorgio Buccellati (1981), "Wisdom and Not: The Case of Mesopotamia", Journal of the American Oriental Society 101 (1), p. 35-47.
- Giorgio Buccellati (1981), "Wisdom and Not: The Case of Mesopotamia", Journal of the American Oriental Society 101 (1), p. 35-47 .
- Ebrey, Patricia (2010). The Cambridge Illustrated History of China. Cambridge University Press. p. 42.
- Juergensmeyer, Mark (2005). Religion in global civil society. Oxford University Press. p. 70.
- Craig 1998, p. 536.
- Oxford Companion to Philosophy
- Process and Reality p. 39
- Cicero, Tusculan Disputations, 5.3.8–9 = Heraclides Ponticus fr. 88 Wehrli, Diogenes Laërtius 1.12, 8.8, Iamblichus VP 58. Burkert attempted to discredit this ancient tradition, but it has been defended by C.J. De Vogel, Pythagoras and Early Pythagoreanism (1966), pp. 97–102, and C. Riedweg, Pythagoras: His Life, Teaching, And Influence (2005), p. 92.
- p 22, The Principal Upanisads, Harper Collins, 1994
- Oxford Dictionary of World Religions, p. 259
- Apte, p. 497.
- Blackburn, Simon (1994). The Oxford Dictionary of Philosophy. Oxford: Oxford University Press.
- Frederick Copleston, A History of Philosophy, Volume II: From Augustine to Scotus (Burns & Oates, 1950), p. 1, dates medieval philosophy proper from the Carolingian Renaissance in the eighth century to the end of the fourteenth century, though he includes John of St. Thomas in the seventeenth century. Anthony Kenny, A New History of Western Philosophy, Volume II: Medieval Philosophy (Oxford University Press, 2005), begins with Augustine and ends with the Lateran Council of 1512.
- Gracia, p. 1
- Charles Schmitt and Quentin Skinner (eds.), The Cambridge History of Renaissance Philosophy (Cambridge University Press, 1988), p. 5, loosely define the period as extending "from the age of Ockham to the revisionary work of Bacon, Descartes and their contemporaries."
- Frederick Copleston, A History of Philosophy, Volume III: From Ockham to Suarez (The Newman Press, 1953) p. 18: "When one looks at Renaissance philosophy ... one is faced at first sight with a rather bewildering assortment of philosophies."
- Brian Copenhaver and Charles Schmitt, Renaissance Philosophy (Oxford University Press, 1992), p. 4: "one may identify the hallmark of Renaissance philosophy as an accelerated and enlarged interest, stimulated by newly available texts, in primary sources of Greek and Roman thought that were previously unknown or partially known or little read."
- Jorge J.E. Gracia in Nicholas Bunnin and E.P. Tsui-James (eds.), The Blackwell Companion to Philosophy, 2nd ed. (Blackwell, 2002), p. 621: "the humanists ... restored man to the centre of attention and channeled their efforts to the recovery and transmission of classical learning, particularly in the philosophy of Plato."
- Copleston, ibid.: "The bulk of Renaissance thinkers, scholars and scientists were, of course, Christians ... but none the less the classical revival ... helped to bring to the fore a conception of autonomous man or an idea of the development of the human personality, which, though generally Christian, was more 'naturalistic' and less ascetic than the mediaeval conception."
- Charles B. Schmitt and Quentin Skinner (eds.), The Cambridge History of Renaissance Philosophy, pp. 61 and 63: "From Petrarch the early humanists learnt their conviction that the revival of humanae literae was only the first step in a greater intellectual renewal" [...] "the very conception of philosophy was changing because its chief object was now man—man was at centre of every inquiry".
- Cassirer; Kristeller; Randall, eds. (1948). "Introduction". The Renaissance Philosophy of Man. University of Chicago Press.
- Copenhaver and Schmitt, Renaissance Philosophy, pp. 285–328.
- Pico Della Mirandola, Conclusiones philosophicae, cabalisticae et theologicae; Giordano Bruno, De Magia
- Richard Popkin, The History of Scepticism from Savonarola to Bayle (Oxford University Press, 2003).
- Copleston, pp. 228–229.
- Kenny, A New History of Western Philosophy, vol. 3 (Oxford University Press, 2006), p. 8: "The Lutheran Reformation [...] gave new impetus to the sceptical trend."
- "Machiavelli appears as the first modern political thinker" Williams, Garrath. "Hobbes: Moral and Political Philosophy". Internet Encyclopedia of Philosophy.. "Machiavelli ought not really to be classified as either purely an "ancient" or a "modern," but instead deserves to be located in the interstices between the two." Nederman, Cary. "Niccolò Machiavelli". Stanford Encyclopedia of Philosophy.
- Copenhaver and Schmitt, Renaissance Philosophy, pp. 274–284.
- Schmitt and Skinner, The Cambridge History of Renaissance Philosophy, pp. 430–452.
- Blocker, H. Gene; Starling, Christopher L. (2001). Japanese Philosophy. SUNY Press. p. 64.
- Huang 1999, p. 5.
- Chan 2002, p. 460.
- Sharma, Peri Sarveswara (1980). Anthology of Kumārilabhaṭṭa's Works. Delhi, Motilal Banarsidass. p. 5.
- "Consciousness in Advaita Vedānta ," By William M. Indich, Motilal Banarsidass Publishers, 1995, ISBN 978-81-208-1251-2.
- "Gandhi And Mahayana Buddhism". Class.uidaho.edu. Retrieved 2011-06-10.
- Wainwright, William, "Concepts of God", The Stanford Encyclopedia of Philosophy (Winter 2010 Edition), Edward N. Zalta (ed.)
- Donald Rutherford, The Cambridge Companion to Early Modern Philosophy (Cambridge University Press, 2006), p. xiii, defines its subject thus: "what has come to be known as "early modern philosophy"—roughly, philosophy spanning the period between the end of the sixteenth century and the end of the eighteenth century, or, in terms of figures, Montaigne through Kant." Steven Nadler, A Companion to Early Modern Philosophy (Blackwell, 2002), p. 1, likewise identifies its subject as "the seventeenth and eighteenth centuries". Anthony Kenny, The Oxford History of Western Philosophy (Clarendon: Oxford University Press, 1994), p. 107, introduces "early modern philosophy" as "the writings of the classical philosophers of the seventeenth and eighteenth centuries in Europe".
- Steven Nadler, A Companion to Early Modern Philosophy, pp. 1–2: "By the seventeenth century [...] it had become more common to find original philosophical minds working outside the strictures of the university—i.e., ecclesiastic—framework. [...] by the end of the eighteenth century, [philosophy] was a secular enterprise."
- Anthony Kenny, A New History of Western Philosophy, vol. 3 (Oxford University Press, 2006), p. xii: "To someone approaching the early modern period of philosophy from an ancient and medieval background the most striking feature of the age is the absence of Aristotle from the philosophic scene."
- Donald Rutherford, The Cambridge Companion to Early Modern Philosophy (Cambridge University Press, 2006), p. 1: "epistemology assumes a new significance in the early modern period as philosophers strive to define the conditions and limits of human knowledge."
- Kenny, A New History of Western Philosophy, vol. 3, p. 211: "The period between Descartes and Hegel was the great age of metaphysical system-building."
- Kenny, A New History of Western Philosophy, vol. 3, pp. 179–180: "the seventeenth century saw the gradual separation of the old discipline of natural philosophy into the science of physics [...] [b]y the nineteenth century physics was a fully mature empirical science, operating independently of philosophy."
- Kenny, A New History of Western Philosophy, vol. 3, pp. 212–331.
- Nadler, A Companion to Early Modern Philosophy, pp. 2–3: "Why should the early modern period in philosophy begin with Descartes and Bacon, for example, rather than with Erasmus and Montaigne? [...] Suffice it to say that at the beginning of the seventeenth century, and especially with Bacon and Descartes, certain questions and concerns come to the fore—a variety of issues that motivated the inquiries and debates that would characterize much philosophical thinking for the next two centuries."
- "Hobbes: Moral and Political Philosophy". Internet Encyclopedia of Philosophy. "Hobbes is the founding father of modern political philosophy. Directly or indirectly, he has set the terms of debate about the fundamentals of political life right into our own times."
- "Contractarianismtitle=Stanford Encyclopedia of Philosophy". http://plato.stanford.edu/entries/contractarianism/. : "Contractarianism [...] stems from the Hobbesian line of social contract thought"
- Rutherford, The Cambridge Companion to Early Modern Philosophy, p. 1: "Most often this [period] has been associated with the achievements of a handful of great thinkers: the so-called 'rationalists' (Descartes, Spinoza, Leibniz) and 'empiricists' (Locke, Berkeley, Hume), whose inquiries culminate in Kant's 'Critical philosophy.' These canonical figures have been celebrated for the depth and rigor of their treatments of perennial philosophical questions..."
- Nadler, A Companion to Early Modern Philosophy, p. 2: "The study of early modern philosophy demands that we pay attention to a wide variety of questions and an expansive pantheon of thinkers: the traditional canonical figures (Descartes, Spinoza, Leibniz, Locke, Berkeley, and Hume), to be sure, but also a large 'supporting cast'..."
- Bruce Kuklick, "Seven Thinkers and How They Grew: Descartes, Spinoza, Leibniz; Locke, Berkeley, Hume; Kant" in Rorty, Schneewind, and Skinner (eds.), Philosophy in History (Cambridge University Press, 1984), p. 125: "Literary, philosophical, and historical studies often rely on a notion of what is canonical. In American philosophy scholars go from Jonathan Edwards to John Dewey; in American literature from James Fenimore Cooper to F. Scott Fitzgerald; in political theory from Plato to Hobbes and Locke [...] The texts or authors who fill in the blanks from A to Z in these, and other intellectual traditions, constitute the canon, and there is an accompanying narrative that links text to text or author to author, a 'history of' American literature, economic thought, and so on. The most conventional of such histories are embodied in university courses and the textbooks that accompany them. This essay examines one such course, the History of Modern Philosophy, and the texts that helped to create it. If a philosopher in the United States were asked why the seven people in my title comprise Modern Philosophy, the initial response would be: they were the best, and there are historical and philosophical connections among them."
- Rutherford, The Cambridge Companion to Early Modern Philosophy, p. 1.
- Kenny, A New History of Western Philosophy, vol. 3, p. xiii.
- Nadler, A Companion to Early Modern Philosophy, p. 3.
- Shand, John (ed.) Central Works of Philosophy, Vol.3 The Nineteenth Century (McGill-Queens, 2005)
- Thomas Baldwin (ed.), The Cambridge History of Philosophy 1870–1945 (Cambridge University Press, 2003), p. 4: "by the 1870s Germany contained much of the best universities in the world. [...] There were certainly more professors of philosophy in Germany in 1870 than anywhere else in the world, and perhaps more even than everywhere else put together."
- Beiser, Frederick C. The Cambridge Companion to Hegel, (Cambridge, 1993).
- Baldwin (ed.), The Cambridge History of Philosophy 1870–1945, p. 119: "within a hundred years of the first stirrings in the early nineteenth century [logic] had undergone the most fundamental transformation and substantial advance in its history."
- Scott Soames, Philosophical Analysis in the Twentieth Century, vol. 2, p. 463.
- Paul Edwards (ed.), Encyclopedia of Philosophy, vol. 7 (Macmillan, 1967), p. 239: "Russell has exercised an influence on the course of Anglo-American philosophy in the twentieth century second to that of no other individual."
- Thomas Baldwin (ed.), The Cambridge History of Philosophy 1870–1945 (Cambridge University Press, 2003), p. 376: "[...] the three greatest European philosophers of the twentieth century—Heidegger, Russell, and Wittgenstein."
- Avrum Stroll, Twentieth-Century Analytic Philosophy (Columbia University Press, 2000), p. 252: "More than any other analytic philosopher, [Wittgenstein] has changed the thinking of a whole generation."
- "Wittgenstein, Ludwig" in the Internet Encyclopedia of Philosophy: "Ludwig Wittgenstein is one of the most influential philosophers of the twentieth century, and regarded by some as the most important since Immanuel Kant."
- Thomas Baldwin, Contemporary Philosophy (Oxford University Press, 2001), p. 90: "[Quine] has been, without question, the most influential American philosopher of the second half of the twentieth century."
- Peter Hylton, "Quine", in the Stanford Encyclopedia of Philosophy: "Quine's work has been extremely influential and has done much to shape the course of philosophy in the second-half of the twentieth century and into the twenty-first."
- Andrew Bailey, First Philosophy: Knowledge and Reality (Broadview Press, 2004), p. 274: "Willard Van Orman Quine (1908–2000) was uncontroversially one of the most important philosophers of the twentieth century."
- Anthony Kenny, Philosophy in the Modern World (Oxford University Press, 2007), p. 64: "After Wittgenstein's death many people regarded W.V.O. Quine (1908–2000) as the doyen of Anglophone philosophy."
- Stanford Encyclopedia of Philosophy : "David Lewis (1941–2001) was one of the most important philosophers of the 20th Century. He made significant contributions to philosophy of language, philosophy of mathematics, philosophy of science, decision theory, epistemology, meta-ethics and aesthetics. In most of these fields he is essential reading; in many of them he is among the most important figures of recent decades. And this list leaves out his two most significant contributions."
- John Perry, Michael Bratman, John Martin Fischer (eds.), Introduction to Philosophy: Classical and Contemporary Readings, 4th ed. (Oxford University Press, 2006), p. 302: "David Lewis (1941–2001) was one of the most important philosophers of the twentieth century."
- "Edmund Husserl", in The Stanford Encyclopedia of Philosophy: "Edmund Husserl was the principal founder of phenomenology—and thus one of the most influential philosophers of the 20th century."
- "Husserl, Edmund", in the Internet Encyclopedia of Philosophy: "he is arguably one of the most important and influential philosophers of the twentieth century."
- Raymond Geuss, in Thomas Baldwin (ed.), The Cambridge History of Philosophy 1870–1945 (Cambridge University Press, 2003), p. 497: "Heidegger is by a wide margin the single most influential philosopher of the twentieth century."
- "Heidegger, Martin", in the Internet Encyclopedia of Philosophy: "Martin Heidegger is widely acknowledged to be one of the most original and important philosophers of the 20th century".
- Kant, Immanuel (1990). Critique of Pure Reason. Prometheus Books.
- Peirce, C. S. (1878), "How to Make Our Ideas Clear", Popular Science Monthly, v. 12, 286–302. Reprinted often, including Collected Papers v. 5, paragraphs 388–410 and Essential Peirce v. 1, 124–41. See end of §II for the pragmatic maxim. See third and fourth paragraphs in §IV for the discoverability of truth and the real by sufficient investigation. Also see quotes from Peirce from across the years in the entries for "Truth" and "Pragmatism, Maxim of..." in the Commens Dictionary of Peirce's Terms, Mats Bergman and Sami Paavola, editors, University of Helsinki.
- Peirce on p. 293 of "How to Make Our Ideas Clear", Popular Science Monthly, v. 12, pp. 286–302. Reprinted widely, including Collected Papers of Charles Sanders Peirce (CP) v. 5, paragraphs 388–410.
- Rorty, Richard (1982). The Consequences of Pragmatism. Minnesota: Minnesota University Press. p. xvi.
- Putnam, Hilary (1995). Pragmatism: An Open Question. Oxford: Blackwell. pp. 8–12.
- Pratt, J. B. (1909). What is Pragmatism?. New York: Macmillan. p. 89.
- Woodruff Smith, David (2007). Husserl. Routledge.
- Dreyfus, Hubert (2006). A Companion to Phenomenology and Existentialism. Blackwell.
- John Macquarrie, Existentialism, New York (1972), pages 18–21.
- Oxford Companion to Philosophy, ed. Ted Honderich, New York (1995), page 259.
- John Macquarrie, Existentialism, New York (1972), pages 14–15.
- Robert C. Solomon, Existentialism (McGraw-Hill, 1974, pages 1–2)
- Ernst Breisach, Introduction to Modern Existentialism, New York (1962), page 5
- Walter Kaufmann, Existentialism: From Dostoevesky to Sartre, New York (1956) page 12
- Matustik, Martin J. (1995). Kierkegaard in Post/Modernity. Indiana University Press.
- Solomon, Robert (2001). What Nietzsche Really Said. Schocken.
- Religious thinkers were among those influenced by Kierkegaard. Christian existentialists include Gabriel Marcel, Nicholas Berdyaev, Miguel de Unamuno, and Karl Jaspers (although he preferred to speak of his "philosophical faith"). The Jewish philosophers Martin Buber and Lev Shestov have also been associated with existentialism.
- Kierkegaard, Søren (1986). Fear and Trembling. Penguin Classics.
- Kierkegaard, Søren (1992). Concluding Unscientific Postscript. Princeton University Press.
- Russell, Bertrand (1999-02-22). (1903)"The Principles of Mathematics". Fair-use.org. Retrieved 2010-08-22.
- Bullock, Alan, R. B. Woodings, and John Cumming, eds. The Fontana Dictionary of Modern Thinkers, in series, Fontana Original[s]. Hammersmith, Eng.: Fontana Press, 1992, cop. 1983. xxv, 867 p. ISBN 978-0-00-636965-3
- Bullock, Alan, and Oliver Stallybrass, jt. eds. The Harper Dictionary of Modern Thought. New York: Harper & Row, 1977. xix, 684 p. N.B.: "First published in England under the title, The Fontana Dictionary of Modern Thought." ISBN 978-0-06-010578-5
- Julia, Didier. Dictionnaire de la philosophie. Responsible éditorial, Emmanuel de Waresquiel; secretariat de rédaction, Joelle Narjollet. [Éd. rev.]. Paris: Larousse, 2006. 301,  p. + xvi p. of ill. ISBN 978-2-03-583309-9
- Reese, W. L. Dictionary of Philosophy and Religion: Eastern and Western Thought. Atlantic Highlands, N.J.: Humanities Press, 1980. iv, 644 p. ISBN 978-0-391-00688-1
- Appiah, Kwame Anthony. Thinking it Through – An Introduction to Contemporary Philosophy, 2003, ISBN 978-0-19-513458-2
- Blumenau, Ralph. Philosophy and Living. ISBN 978-0-907845-33-1
- Craig, Edward. Philosophy: A Very Short Introduction. ISBN 978-0-19-285421-6
- Curley, Edwin, A Spinoza Reader, Princeton, 1994, ISBN 978-0-691-00067-1
- Durant, Will, Story of Philosophy: The Lives and Opinions of the World's Greatest Philosophers, Pocket, 1991, ISBN 978-0-671-73916-4
- Harrison-Barbet, Anthony, Mastering Philosophy. ISBN 978-0-333-69343-8
- Higgins, Kathleen M. and Solomon, Robert C. A Short History of Philosophy. ISBN 978-0-19-510196-6
- Philosophy Now magazine
- Russell, Bertrand. The Problems of Philosophy. ISBN 978-0-19-511552-9
- Sinclair, Alistair J. What is Philosophy? An Introduction, 2008, ISBN 978-1-903765-94-4
- Sober, Elliott. (2001). Core Questions in Philosophy: A Text with Readings. Upper Saddle River, Prentice Hall. ISBN 978-0-13-189869-1
- Solomon, Robert C. Big Questions: A Short Introduction to Philosophy. ISBN 978-0-534-16708-0
- Warburton, Nigel. Philosophy: The Basics. ISBN 978-0-415-14694-4
- Think: philosophy for everyone Lively and accessible articles written by philosophers pre-eminent in their fields, for a broad audience. Free articles are available online.
- Gerald Rochelle  Doing Philosophy, 2012, ISBN 978-1-78046-004-8
- Copleston, Frederick. Philosophy in Russia: From Herzen to Lenin and Berdyaev. ISBN 978-0-268-01569-5
- Critchley, Simon. Continental Philosophy: A Very Short Introduction. ISBN 978-0-19-285359-2
- Hamilton, Sue. Indian Philosophy: a Very Short Introduction. ISBN 978-0-19-285374-5
- Harwood, Sterling, ed., Business as Ethical and Business as Usual (Belmont, CA: Wadsworth Publishing Co., 2000); www.sterlingharwood.com
- Imbo, Samuel Oluoch. '3'An Introduction to African Philosophy. ISBN 978-0-8476-8841-8
- Knight, Kelvin. Aristotelian Philosophy: Ethics and Politics from Aristotle to MacIntyre. ISBN 978-0-7456-1977-4
- Kupperman, Joel J. Classic Asian Philosophy: A Guide to the Essential Texts. ISBN 978-0-19-513335-6
- Leaman, Oliver. A Brief Introduction to Islamic Philosophy. ISBN 978-0-7456-1960-6
- Lee, Joe and Powell, Jim. Eastern Philosophy For Beginners. ISBN 978-0-86316-282-4
- Nagel, Thomas. What Does It All Mean? A Very Short Introduction to Philosophy. ISBN 978-0-19-505292-3
- Scruton, Roger. A Short History of Modern Philosophy. ISBN 978-0-415-26763-2
- Smart, Ninian. World Philosophies. ISBN 978-0-415-22852-7
- Tarnas, Richard. The Passion of the Western Mind: Understanding the Ideas That Have Shaped Our World View. ISBN 978-0-345-36809-6
- Classics of Philosophy (Vols. 1 & 2, 2nd edition) by Louis P. Pojman
- Classics of Philosophy: The 20th Century (Vol. 3) by Louis P. Pojman
- The English Philosophers from Bacon to Mill by Edwin Arthur
- European Philosophers from Descartes to Nietzsche by Monroe Beardsley
- Contemporary Analytic Philosophy: Core Readings by James Baillie
- Existentialism: Basic Writings (Second Edition) by Charles Guignon, Derk Pereboom
- The Phenomenology Reader by Dermot Moran, Timothy Mooney
- Medieval Islamic Philosophical Writings edited by Muhammad Ali Khalidi
- A Source Book in Indian Philosophy by Sarvepalli Radhakrishnan, Charles A. Moore
- A Source Book in Chinese Philosophy by Wing-tsit Chan
- Kim, J. and Ernest Sosa, Ed. (1999). Metaphysics: An Anthology. Blackwell Philosophy Anthologies. Oxford, Blackwell Publishers Ltd.
- The Oxford Handbook of Free Will (2004) edited by Robert Kane
- Husserl, Edmund and Donn Welton (1999). The Essential Husserl: Basic Writings in Transcendental Phenomenology, Indiana University Press. ISBN 978-0-253-21273-3
- Cottingham, John. Western Philosophy: An Anthology. 2nd ed. Malden, MA: Blackwell Pub., 2008. Print. Blackwell Philosophy Anthologies.
- Chan, Wing-tsit (1963). A Source Book in Chinese Philosophy. Princeton University Press.
- Huang, Siu-chi (1999). Essentials of Neo-Confucianism: Eight Major Philosophers of the Song and Ming Periods. Greenwood Publishing Group.
- The Oxford Companion to Philosophy edited by Ted Honderich
- The Cambridge Dictionary of Philosophy by Robert Audi
- The Routledge Encyclopedia of Philosophy (10 vols.) edited by Edward Craig, Luciano Floridi (available online by subscription); or
- The Concise Routledge Encyclopedia of Philosophy edited by Edward Craig (an abridgement)
- Encyclopedia of Philosophy (8 vols.) edited by Paul Edwards; in 1996, a ninth supplemental volume appeared that updated the classic 1967 encyclopedia.
- International Directory of Philosophy and Philosophers. Charlottesville, Philosophy Documentation Center.
- Directory of American Philosophers. Charlottesville, Philosophy Documentation Center.
- Routledge History of Philosophy (10 vols.) edited by John Marenbon
- History of Philosophy (9 vols.) by Frederick Copleston
- A History of Western Philosophy (5 vols.) by W. T. Jones
- History of Italian Philosophy (2 vols.) by Eugenio Garin. Translated from Italian and Edited by Giorgio Pinton. Introduction by Leon Pompa.
- Encyclopaedia of Indian Philosophies (8 vols.), edited by Karl H. Potter et al. (first 6 volumes out of print)
- Indian Philosophy (2 vols.) by Sarvepalli Radhakrishnan
- A History of Indian Philosophy (5 vols.) by Surendranath Dasgupta
- History of Chinese Philosophy (2 vols.) by Fung Yu-lan, Derk Bodde
- Instructions for Practical Living and Other Neo-Confucian Writings by Wang Yang-ming by Chan, Wing-tsit
- Encyclopedia of Chinese Philosophy edited by Antonio S. Cua
- Encyclopedia of Eastern Philosophy and Religion by Ingrid Fischer-Schreiber, Franz-Karl Ehrhard, Kurt Friedrichs
- Companion Encyclopedia of Asian Philosophy by Brian Carr, Indira Mahalingam
- A Concise Dictionary of Indian Philosophy: Sanskrit Terms Defined in English by John A. Grimes
- History of Islamic Philosophy edited by Seyyed Hossein Nasr, Oliver Leaman
- History of Jewish Philosophy edited by Daniel H. Frank, Oliver Leaman
- A History of Russian Philosophy: From the Tenth to the Twentieth Centuries by Valerii Aleksandrovich Kuvakin
- Ayer, A.J. et al., Ed. (1994) A Dictionary of Philosophical Quotations. Blackwell Reference Oxford. Oxford, Basil Blackwell Ltd.
- Blackburn, S., Ed. (1996)The Oxford Dictionary of Philosophy. Oxford, Oxford University Press.
- Mauter, T., Ed. The Penguin Dictionary of Philosophy. London, Penguin Books.
- Runes, D., Ed. (1942). The Dictionary of Philosophy. New York, The Philosophical Library, Inc.
- Angeles, P.A., Ed. (1992). The Harper Collins Dictionary of Philosophy. New York, Harper Perennial.
- Bunnin, N. et al., Ed. (1996) The Blackwell Companion to Philosophy. Blackwell Companions to Philosophy. Oxford, Blackwell Publishers Ltd.
- Hoffman, Eric, Ed. (1997) Guidebook for Publishing Philosophy. Charlottesville, Philosophy Documentation Center.
- Popkin, R.H. (1999). The Columbia History of Western Philosophy. New York, Columbia University Press.
Library resources about
- Stanford Encyclopedia of Philosophy
- The Internet Encyclopedia of Philosophy
- Indiana Philosophy Ontology Project
- PhilPapers - a comprehensive directory of online philosophical articles and books by academic philosophers
- Philosophy Timeline
- Map of Western Philosophers
- Philosophy Magazines and Journals
- Philosophy at DMOZ
- Philosophy (review)
- Philosophy – OpenCourseWare from the University of Notre Dame
- Philosophy Documentation Center
- Popular Philosophy