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Philosophy (love of wisdom in ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, value, mind, and language. It is a rational and critical inquiry that reflects on its own methods and assumptions.


Historically, many of the individual sciences, like physics and psychology, formed part of philosophy. But they are considered separate academic disciplines in the modern sense of the term. The main traditions in the history of philosophy include Western, Arabic-Persian, Indian, and Chinese philosophy. Western philosophy originated in Ancient Greece and covers a wide area of philosophical subfields. A central topic in Arabic-Persian philosophy is the relation between reason and revelation. Indian philosophy combines the spiritual problem of how to reach enlightenment with the exploration of the nature of reality and the ways of arriving at knowledge. Chinese philosophy focuses on practical issues in relation to right social conduct, government, and self-cultivation.

Major branches of philosophy are epistemology, ethics, logic, and metaphysics. Epistemology studies what knowledge is and how to acquire it. Ethics investigates moral principles and what constitutes right conduct. Logic is the study of correct reasoning and explores how good arguments can be distinguished from bad ones. Metaphysics examines the most general features of reality, existence, objects, and properties. Other notable subfields are aesthetics, philosophy of language, philosophy of mind, philosophy of religion, philosophy of science, philosophy of history, and political philosophy.

Philosophers use a great variety of methods to arrive at philosophical knowledge. They include conceptual analysis, reliance on common sense and intuitions, use of thought experiments, analysis of ordinary language, description of experience, and critical questioning. Philosophy is related to many other fields, like the sciences, mathematics, business, law, and journalism. It provides an interdisciplinary perspective and studies their scope and fundamental concepts. It also investigates their methods and ethical implications.


The word "philosophy" comes from the ancient Greek words φίλος (philos: "love") and σοφία (sophia: "wisdom"). [1] [2] [3] Some sources say that the term was coined by the Presocratic philosopher Pythagoras, but this is not certain. [4] [5]

Physics was originally part of philosophy, like Isaac Newton's observation of how gravity affects falling apples. Doctor Zirkel follows Newton's famous steps under the fabled Wellcome V0011942.jpg
Physics was originally part of philosophy, like Isaac Newton's observation of how gravity affects falling apples.

The word entered the English language primarily from Old French and Anglo-Norman starting around 1175 CE. The French philosophie is itself a borrowing from the Latin philosophia. The term philosophy acquired the meanings of "advanced study of the speculative subjects (logic, ethics, physics, and metaphysics)", "deep wisdom consisting of love of truth and virtuous living", "profound learning as transmitted by the ancient writers", and "the study of the fundamental nature of knowledge, reality, and existence, and the basic limits of human understanding". [6] [1]

Before the modern age, the term philosophy was used in a wide sense. It included most forms of rational inquiry, like the individual sciences, as its subdisciplines. [1] [7] [8] For instance, natural philosophy was a major branch of philosophy. [9] [10] [11] [12] This branch of philosophy encompassed a wide range of fields, including disciplines like physics, chemistry, and biology. [1] [13] An example of this usage is the 1687 book Philosophiæ Naturalis Principia Mathematica by Isaac Newton. This book referred to natural philosophy in its title, but it is today considered a book of physics. [11] [12] [14]

The meaning of philosophy changed toward the end of the modern period when it acquired the more narrow meaning common today. In this new sense, the term is mainly associated with philosophical disciplines like metaphysics, epistemology, and ethics. Among other topics, it covers the rational study of reality, knowledge, and values. However, it is distinguished from other disciplines of rational inquiry like the empirical sciences and mathematics. [15]

Conceptions of philosophy

General conception

The practice of philosophy is characterized by various general features: it is a form of rational inquiry, it aims to be systematic, and it tends to critically reflect on its own methods and presuppositions. [16] It requires thinking "as hard and as clearly...about some of the most interesting and enduring problems that human minds have ever encountered". [17]

According to the 18th-century philosopher Immanuel Kant, the task of philosophy is united by four questions: (1) What can I know?; (2) What should I do?; (3) What may I hope?; and (4) What is the human being? His entire career, as he conceived it, was devoted to systematically addressing these four questions. [18] [19] [20]

The theme of self-critical intellectual humility may be traced back to the origins of Western philosophy. Socrates, as depicted in Plato's dialogues, famously expresses incredulity when told by the Oracle at Delphi that he is the wisest person of all. What he comes to conclude is that his wisdom consists in his knowing that he does not possess the most exalted kind of wisdom, namely, that about what is truly fine and good. [21] [22] Consistent with his well-known assertion that "the unexamined life is not worth living", Socrates arrives at the conclusion that the active pursuit of wisdom is good and valuable in itself, irrespective of whether one ever arrives at final definitions. [23] [24] This is consistent with the view that the kind of knowledge that philosophy seeks is not information, but understanding. [25]

Confronting the unlikelihood of ever arriving at final answers to the great questions of philosophy, Bertrand Russell offers this justification for nevertheless undertaking the labor: "The man who has no tincture of philosophy goes through life imprisoned in the prejudices derived from common sense, from the habitual beliefs of his age or his nation, and from convictions which have grown up in his mind without the cooperation or consent of his deliberate reason." [26] [27] This passage has been cited to advance an interpretation of philosophy as "freeing us from prejudice, self-deceptive notions, and half-truths". [28]

Academic definitions

Attempts to define philosophy in precise terms are controversial [29] [14] and are studied in the subdiscipline known as metaphilosophy. [30] Some approaches argue that there is a set of essential features shared by all parts of philosophy. Others see only weaker family resemblances or contend that it is merely an empty blanket term. [31] [32] [33] Precise definitions are often only accepted by theorists belonging to a certain philosophical movement and are revisionistic according to Søren Overgaard et al. in that many presumed parts of philosophy would not deserve the title "philosophy" if they were true. [34] [35]

Some definitions characterize philosophy in relation to its method, like pure reasoning. Others focus on its topic, for example, as the study of the biggest patterns of the world as a whole or as the attempt to answer the big questions. [36] [37] [38] Both approaches have the problem that they are usually either too wide, by including non-philosophical disciplines, or too narrow, by excluding some philosophical sub-disciplines. [36]

Many definitions of philosophy emphasize its intimate relation to science. [14] In this sense, philosophy is sometimes understood as a proper science in its own right. According to some naturalistic philosophers, like W. V. O. Quine, philosophy is an empirical yet abstract science that is concerned with wide-ranging empirical patterns instead of particular observations. [39] [40] Science-based definitions usually face the problem of explaining why philosophy in its long history has not made the type of progress seen in other sciences. [41] [42] [43] This problem is avoided by seeing philosophy as an immature or provisional science whose subdisciplines cease to be philosophy once they have fully developed. [14] [32] [44] In this sense, philosophy is sometimes described as "the midwife of the sciences". [45] [14]

Other definitions focus on the contrast between science and philosophy. A common theme among many such conceptions is that philosophy is concerned with meaning, understanding, or the clarification of language. [46] [47] According to one view, philosophy is conceptual analysis, which involves finding the necessary and sufficient conditions for the application of concepts. [48] [38] [49]

Phenomenologists, such as Edmund Husserl, characterize philosophy as a "rigorous science" investigating essences. [50] They practice a radical suspension of theoretical assumptions about reality in order to get back to the "things themselves", that is, as originally given in experience. They contend that this base-level of experience provides the foundation for higher-order theoretical knowledge, and that one needs to understand the former in order to understand the latter. [51]

Another approach presents philosophy as a linguistic therapy. According to Ludwig Wittgenstein, for example, philosophy aims at dispelling misunderstandings to which humans are susceptible due to the confusing structure of natural language. [14] [52] [53]

An early approach found in ancient Greek and Roman philosophy, and later adopted by 20th-century philosophers such as Michel Foucault and Pierre Hadot, is that philosophy is the spiritual practice of developing one's rational capacities. [54] [55] This practice is an expression of the philosopher's love of wisdom and has the aim of improving one's well-being by leading a reflective life. [56]

Another definition characterizes philosophy as thinking about thinking. This emphasizes its self-critical, reflective nature. [57] [58]


As a discipline, the history of philosophy aims to provide a systematic and chronological exposition of philosophical concepts and doctrines. [59] [60] [61] Some theorists see it as a part of intellectual history, but it also investigates questions not covered by intellectual history such as whether the theories of past philosophers are true and have remained philosophically relevant. [62] The history of philosophy is primarily concerned with theories based on rational inquiry and argumentation. However, some historians understand it in a looser sense that includes myths, religious teachings, and proverbial lore. [63]

The main traditions in the history of philosophy include Western, Arabic-Persian, Indian, and Chinese philosophy. Other influential philosophical traditions are Japanese philosophy, Latin American philosophy, and African philosophy. [64]


Statue of Aristotle, a major figure of ancient Greek philosophy, in Aristotle's Park, Stagira Aristoteles der Stagirit.jpg
Statue of Aristotle, a major figure of ancient Greek philosophy, in Aristotle's Park, Stagira

Western philosophy originated in Ancient Greece in the 6th century BCE with the Presocratics. They attempted to provide rational explanations of the cosmos as a whole. [65] [66] [67] The philosophy following them was shaped by Socrates (469–399 BCE), Plato (427–347 BCE), and Aristotle (384–322 BCE). They expanded the range of topics to questions like how people should act, how to arrive at knowledge, and what the nature of reality and mind is. [68] [69] The later part of the ancient period was marked by the emergence of philosophical movements like Epicureanism, Stoicism, Skepticism, and Neoplatonism. [70] [71] [72] The medieval period started in the 5th century CE. Its focus was on religious topics and many thinkers used ancient philosophy to explain and further elaborate Christian doctrines. [73] [74] [75]

The Renaissance period started in the 14th century and saw a renewed interest in various schools of Ancient philosophy, in particular Platonism. Humanism also emerged in this period. [76] The modern period started in the 17th century. One of its central concerns was how philosophical and scientific knowledge are created. Specific importance was given to the role of reason and sensory experience. [77] [78] Many of these innovations were used in the Enlightenment movement to challenge traditional authorities. [79] [80] Various attempts to develop all-inclusive systems of philosophy were made in the 19th century, for example, by German idealism. [81] Influential developments in 20th-century philosophy were the emergence and application of formal logic and the focus on the role of language as well as pragmatism and movements in continental philosophy like phenomenology, existentialism, and postmodernism. [82] [83] The 20th century saw a rapid expansion of academic philosophy in terms of the number of philosophical publications and philosophers working at academic institutions. [82] There was also a noticeable growth in the number of female philosophers, but they still remained underrepresented. [84]


Arabic-Persian philosophy arose in the early 9th century CE as a response to discussions in the Islamic theological tradition. Its classical period lasted until the 12th century CE and was strongly influenced by Ancient Greek philosophers. It employed their ideas to elaborate and interpret the teachings of the Quran. [85]

An Iranian portrait of Avicenna on a Silver Vase. He was one of the most influential philosophers of the Islamic Golden Age. Avicenna Portrait on Silver Vase - Museum at BuAli Sina (Avicenna) Mausoleum - Hamadan - Western Iran (7423560860).jpg
An Iranian portrait of Avicenna on a Silver Vase. He was one of the most influential philosophers of the Islamic Golden Age.

Al-Kindi (801–873 CE) is usually regarded as the first philosopher of this tradition. He translated and interpreted many works of Aristotle and Neoplatonists in his attempt to show that there is a harmony between reason and faith. [86] Avicenna (980–1037 CE) also followed this goal and developed a comprehensive philosophical system to provide a rational understanding of reality encompassing science, religion, and mysticism. [87] [88] Al-Ghazali (1058–1111 CE) was a strong critic of the idea that reason can arrive at a true understanding of reality and God. He formulated a detailed critique of philosophy and tried to assign philosophy a more limited place besides the teachings of the Quran and mystical insight. [89] Following Al-Ghazali and the end of the classical period, the influence of philosophical inquiry waned. [90] [91] Mulla Sadra (1571–1636 CE) is often regarded as one of the most influential philosophers of the subsequent period. [92] [93] The increasing influence of Western thought and institutions in the 19th and 20th centuries gave rise to the intellectual movement of Islamic modernism, which aims to understand the relation between traditional Islamic beliefs and modernity. [94] [95] [96]


One of the distinguishing features of Indian philosophy is that it integrates the exploration of the nature of reality, the ways of arriving at knowledge, and the spiritual question of how to reach enlightenment. [97] [98] It started around 900 BCE when the Vedas were written. They are the foundational scriptures of Hinduism and contemplate issues concerning the relation between the self and ultimate reality as well as the question of how souls are reborn based on their past actions. [99] This period also saw the emergence of non-Vedic teachings, like Buddhism and Jainism. [100] [101] Buddhism was founded by Gautama Siddhartha (563–483 BCE), who challenged the Vedic idea of a permanent self and proposed a path to liberate oneself from suffering. [100] [101] Jainism was founded by Mahavira (599–527 BCE), who emphasized non-violence as well as respect toward all forms of life. [100] [102] [103]

The subsequent classical period started roughly 200 BCE and was characterized by the emergence of the six orthodox schools of Hinduism: Nyāyá, Vaiśeṣika, Sāṃkhya, Yoga, Mīmāṃsā, and Vedanta. [104] [105] [106] The school of Advaita Vedanta developed later in this period. It was systematized by Adi Shankara (c.700–750 CE), who held that everything is one and that the impression of a universe consisting of many distinct entities is an illusion. [107] [108] [109] A slightly different perspective was defended by Ramanuja (1017–1137 CE) [lower-alpha 1] , who founded the school of Vishishtadvaita Vedanta and argued that individual entities are real as aspects or parts of the underlying unity. [111] He also helped to popularize the Bhakti movement, which taught devotion toward the divine as a spiritual path and lasted until the 17th to 18th centuries CE. [112] The modern period began roughly 1800 CE and was shaped by the encounter with Western thought. [113] [114] Various philosophers tried to formulate comprehensive systems to harmonize diverse philosophical and religious teachings. For example, Swami Vivekananda (1863–1902 CE) used the teachings of Advaita Vedanta to argue that all the different religions are valid paths toward the one divine. [115]


The teachings of Confucius on ethics and society shaped subsequent Chinese philosophy. Half Portraits of the Great Sage and Virtuous Men of Old - Confucius.jpg
The teachings of Confucius on ethics and society shaped subsequent Chinese philosophy.

Chinese philosophy is particularly interested in practical questions associated with right social conduct, government, and self-cultivation. [116] In competing attempts to resolve the politically turbulent 6th century BCE, many schools of thought emerged. The most prominent among them were Confucianism and Daoism. [117] [118] Confucianism was founded by Confucius (551–479 BCE). It focused on different forms of moral virtues and explored how they lead to harmony in society. [119] Daoism was founded by Laozi (6th century BCE) and examined how humans can live in harmony with nature by following the Dao or the natural order of the universe. [120] Other influential early schools of thought were Mohism, which developed an early form of altruistic consequentialism, [121] [122] [123] and Legalism, which emphasized the importance of a strong state and strict laws. [121] [124] [125]

Buddhism was introduced to China in the 1st century CE and produced new forms of Buddhism. [126] [127] Starting in the 3rd century CE, the school of Xuanxue emerged. It interpreted earlier Daoist works with a specific emphasis on metaphysical explanations. [126] [127] Neo-Confucianism developed in the 11th century CE. It systematized previous Confucian teachings and sought a metaphysical foundation of ethics. [128] [127] The modern period in Chinese philosophy began in the early 20th century and was shaped by the influence of and reactions to Western philosophy. The emergence of Chinese Marxism—which focused on class struggle, socialism, and communism—resulted in a significant transformation of the political landscape. [129] Another development was the emergence of New Confucianism, which aims to modernize and rethink Confucian teachings to explore their compatibility with democratic ideals and modern science. [130] [131] [132]

Core branches

Philosophical questions can be grouped into various branches. These groupings allow philosophers to focus on a set of similar topics and interact with other thinkers who are interested in the same questions. Epistemology, ethics, logic, and metaphysics are sometimes listed as the main branches. [133] [134] [135] There are many other subfields besides them and the different divisions are neither exhaustive nor mutually exclusive. For example, political philosophy, ethics, and aesthetics are sometimes linked under the general heading of value theory as they investigate normative or evaluative aspects. [136] Furthermore, philosophical inquiry sometimes overlaps with other disciplines in the natural and social sciences, religion, and mathematics. [137] [138]


Epistemology is the branch of philosophy that studies knowledge. It is also known as theory of knowledge and aims to understand what knowledge is, how it arises, what its limits are, and what value it has. It further examines the nature of truth, belief, justification, and rationality. [139] Some of the questions addressed by epistemologists include By what method(s) can one acquire knowledge?; How is truth established?; and Can we prove causal relations? [140]

Epistemology is primarily interested in declarative knowledge or knowledge of facts, like knowing that Princess Diana died in 1997. But it also investigates practical knowledge, like knowing how to ride a bicycle, and knowledge by acquaintance, like knowing a celebrity personally. [141] [142] [143]

One area in epistemology is the analysis of knowledge . It assumes that declarative knowledge is a combination of different parts and attempts to identify what those parts are. An influential theory in this area claims that knowledge has three components: it is (1) a belief that is (2) justified and (3) true. This theory is controversial and the difficulties associated with it are known as the Gettier problem. [144] [145]

Another area in epistemology asks how people acquire knowledge. Often-discussed sources of knowledge are perception, introspection, memory, inference, and testimony. [146] [147] According to empiricists, all knowledge is based on some form of experience. Rationalists reject this view and hold that some forms of knowledge, like innate knowledge, are not acquired through experience. [148] [149] [150] The regress problem is a common issue in relation to the sources of knowledge and the justification they offer. It is based on the idea that beliefs require some kind of reason or evidence to be justified. The problem is that the source of justification may itself be in need of another source of justification. This leads to an infinite regress or circular reasoning. This idea is rejected by foundationalists, who argue that some sources can provide justification without requiring justification themselves. [151] [152] Another solution is presented by coherentists, who state that a belief is justified if it coheres with other beliefs of the person. [153]

Many discussions in epistemology touch on the topic of philosophical skepticism, which raises doubts about some or all claims to knowledge. These doubts are often based on the idea that knowledge requires absolute certainty and that humans are unable to acquire it. [154] [155] [156]


"The utilitarian doctrine is, that happiness is desirable, and the only thing desirable, as an end; all other things being only desirable as means to that end." -- John Stuart Mill, Utilitarianism (1863) JohnStuartMill.jpg
"The utilitarian doctrine is, that happiness is desirable, and the only thing desirable, as an end; all other things being only desirable as means to that end." — John Stuart Mill, Utilitarianism (1863)

Ethics, also known as moral philosophy, studies what constitutes right conduct. It is also concerned with the moral evaluation of character traits and institutions. It explores what the standards of morality are and how to live a good life. [158] [159] [160] Philosophical ethics addresses such basic questions as Are moral obligations relative?; Which has priority: well-being or obligation?; and What gives life meaning? [161]

The main branches of ethics are meta-ethics, normative ethics, and applied ethics. Meta-ethics asks abstract questions about the nature and sources of morality. It analyzes the meaning of ethical concepts, like right action and obligation . It also investigates whether ethical theories can be true in an absolute sense and how to acquire knowledge of them. Normative ethics encompasses general theories of how to distinguish between right and wrong conduct. It helps guide moral decisions by examining what moral obligations and rights people have. Applied ethics studies the consequences of the general theories developed by normative ethics in specific situations, for example, in the workplace or for medical treatments. [162]

Within contemporary normative ethics, consequentialism, deontology, and virtue ethics are influential schools of thought. [163] [164] Consequentialists judge actions based on their consequences. One such view is utilitarianism, which argues that actions should increase overall happiness while minimizing suffering. Deontologists judge actions based on whether they follow moral duties, like abstaining from lying or killing. According to them, what matters is that actions are in tune with those duties and not what consequences they have. Virtue theorists judge actions based on the moral character of the agent who performs them. According to this view, actions should conform to what an ideally virtuous agent would do by manifesting virtues like generosity and honesty. [163] [164] [165]


Logic is the study of correct reasoning. It aims to understand how to distinguish good from bad arguments. [166] [167] It is usually divided into formal and informal logic. Formal logic uses artificial languages with a precise symbolic representation to investigate arguments. In this way, it formulates exact criteria and methods based on the structure of arguments to determine whether they are correct or incorrect. Informal logic uses non-formal criteria and standards to analyze and evaluate the correctness of arguments. It relies on additional factors such as content and context. [168]

Logic examines a variety of arguments. Deductive arguments are mainly studied by formal logic. An argument is deductively valid if the truth of its premises ensures the truth of its conclusion. Deductively valid arguments follow a rule of inference, like modus ponens, which has the following logical form: "p; if p then q; therefore q". An example is the argument "today is Sunday; if today is Sunday then I don't have to go to work today; therefore I don't have to go to work today". [169] [170] [171]

The premises of non-deductive arguments also support their conclusion. However, this support is not as certain and does not guarantee that the conclusion is true. [172] [173] One form is inductive reasoning. It starts from a set of individual cases and uses generalization to arrive at a universal law governing all cases. An example is the inference that "all ravens are black" based on observations of many individual black ravens. [174] [175] [176] Another form is abductive reasoning. It starts from an observation and concludes that the best explanation of this observation must be true. This happens, for example, when a doctor diagnoses a disease based on the observed symptoms. [177] [178] [175]

Logic also investigates incorrect forms of reasoning. They are called fallacies and are divided into formal and informal fallacies based on whether the source of the error lies only in the form of the argument or also in its content and context. [179]


The beginning of Aristotle's Metaphysics in an incunabulum decorated with hand-painted miniatures Aristotle, Metaphysics, Incunabulum.jpg
The beginning of Aristotle's Metaphysics in an incunabulum decorated with hand-painted miniatures

Metaphysics is the study of the most general features of reality, such as existence, objects and their properties, wholes and their parts, space and time, events, and causation. [180] [181] [182] There are disagreements about the precise definition of the term and its meaning has changed throughout the ages. [183] Metaphysicists attempt to answer basic questions like Why is there something rather than nothing?; Of what does reality ultimately consist?; and Are humans free? [184]

Metaphysics is sometimes divided into general metaphysics and specific or special metaphysics. General metaphysics investigates being as such. It examines the features that all entities have in common. Specific metaphysics is interested in different kinds of being, the features they have, and how they differ from one another. [180] [181] [185]

An important area in metaphysics is ontology. Some theorists identify it with general metaphysics. Ontology investigates concepts like being, becoming, and reality. It studies the categories of being and asks what exists on the most fundamental level. [186] Another subfield of metaphysics is philosophical cosmology. It is interested in the essence of the world as a whole. It asks questions like whether the universe has a beginning and an end and whether it was created by something else. [182] [187]

A key topic in metaphysics concerns the question of whether reality only consists of physical things like matter and energy. Alternative suggestions are that mental entities (like souls and experiences) and abstract entities (like numbers) exist apart from physical things. Another topic in metaphysics concerns the problem of identity. It asks questions like how much an entity can change while still remaining the same entity. [182] According to one view, entities have essential and accidental features. They can change their accidental features but they cease to be the same entity if they lose an essential feature. [188] [189] A central distinction in metaphysics is between particulars and universals. Universals, like the color red, can exist at different locations at the same time. This is not the case for particulars, like individual persons or specific objects. [190] [191] Other metaphysical questions are whether the past fully determines the present and what implications this would have for the existence of free will. [192] [193]

Other major branches

There are many additional subfields of philosophy besides its core branches. Some of the most prominent are aesthetics, philosophy of language, philosophy of mind, philosophy of religion, philosophy of science, and political philosophy. [194]

Aesthetics in the philosophical sense is the field that studies the nature and appreciation of beauty and other aesthetic properties, like the sublime. [195] Although it is often treated together with the philosophy of art, aesthetics is a broader category that encompasses other aspects of experience, such as natural beauty. [196] [197] In a more general sense, aesthetics is the "critical reflection on art, culture, and nature". [198] [199] A key question in aesthetics is whether beauty is an objective or mind-independent feature of entities. This view is rejected by subjectivists, who claim that beauty is not an inherent quality of objects, but depends on how people subjectively experience them. [197] [200] Aesthetic philosophers also investigate the nature of aesthetic experiences and judgments. Further topics include the essence of works of art and the processes involved in creating them. [201] [197]

The philosophy of language studies the nature and function of language. It examines the concepts of meaning, reference, and truth. It aims to answer questions like how words are related to things and how language affects human thought and understanding. It is closely related to the disciplines of logic and linguistics. [202] [203] [204] The philosophy of language rose to particular prominence in the early 20th century in analytic philosophy due to the works of Frege and Russell. One of its central topics is to understand how sentences get their meaning. There are two broad theoretical camps: those emphasizing the formal truth conditions of sentences [lower-alpha 2] and those investigating circumstances that determine when it is suitable to use a sentence, the latter of which is associated with speech act theory. [206] [207]

The philosophy of mind studies the nature of mental phenomena and how they are related to the physical world. [208] [209] It aims to understand different types of conscious and unconscious mental states, like beliefs, desires, intentions, feelings, sensations, and free will. [210] [211] An influential intuition in the philosophy of mind is the distinction between an inner world of experience of an object and the existence of this object in the outer world. The mind-body problem is the problem of explaining how matter and mind are related. The main traditional responses are materialism, which assumes that matter is more fundamental; idealism, which assumes that mind is more fundamental; and dualism, which assumes that mind and matter are distinct types of entities. In contemporary philosophy, a widely accepted position is functionalism, which understands mental states in terms of the functional or causal roles they play. [212] The mind-body problem is closely related to the hard problem of consciousness, which asks how the physical brain can produce qualitatively subjective experiences. [213] [214]

The philosophy of religion investigates the basic concepts, assumptions, and arguments associated with religion. It critically reflects on what religion is, how to define the divine, and whether one or more gods exist. It also includes the discussion of worldviews that reject religious doctrines. [215] Further questions addressed by the philosophy of religion are: How are we to interpret religious language, if not literally?; [216] Is divine omniscience compatible with free will?; [217] and, Are the great variety of world religions in some way compatible in spite of their apparently contradictory theological claims? [218] It includes topics from nearly all branches of philosophy. [219] [220] It differs from theology since theological debates typically take place within one religious tradition, while debates in the philosophy of religion transcend any particular set of theological assumptions. [221] [222]

The philosophy of science examines the fundamental concepts, assumptions, and problems associated with science. It reflects on what science is and how to distinguish it from pseudoscience. It investigates the methods employed by scientists, how their application can result in knowledge, and on what assumptions they are based. It also studies the purpose and implications of science. [223] Some of its questions are What counts as an adequate explanation?; [224] Is a scientific law anything more than a description of a regularity?; [225] and Can some special sciences be explained entirely in the terms of a more general science? [226] It is a vast field that is commonly divided into the philosophy of the natural sciences and the philosophy of the social sciences, with further subdivisions for each of the individual sciences under these headings. How these branches are related to one another is also a question in the philosophy of science. Many of its philosophical issues overlap with the fields of metaphysics or epistemology. [227] [228]

Political philosophy is the philosophical inquiry into the fundamental principles and ideas governing political systems and societies. It examines the basic concepts, assumptions, and arguments in the field of politics. It investigates the nature and purpose of government and compares its different forms. [229] It further asks under what circumstances the use of political power is legitimate, rather than a form of simple violence. [230] [231] In this regard, it is concerned with the distribution of political power, social and material goods, as well as legal rights. [232] Other topics are justice, liberty, equality, sovereignty, and nationalism. [230] Political philosophy involves a general inquiry into normative matters and differs in this respect from political science, which aims to provide empirical descriptions of actually existing states. [233] [230] Political philosophy is often treated as a subfield of ethics. [234] Influential schools of thought in political philosophy are liberalism, conservativism, socialism, and anarchism. [235] [236]


Methods of philosophy are ways of conducting philosophical inquiry. They include techniques for arriving at philosophical knowledge and justifying philosophical claims as well as principles used for choosing between competing theories. [237] [238] [239]

A great variety of methods has been employed throughout the history of philosophy. Many of them differ significantly from the methods used in the natural sciences in that they do not use experimental data obtained through measuring equipment. [240] [241] [242]

The choice of one's method usually has important implications both for how philosophical theories are constructed and for the arguments cited for or against them. [243] [244] [245] This choice is often guided by epistemological considerations about what constitutes philosophical evidence. [246] [247] [248]

Methodological disagreements can cause conflicts among philosophical theories or about the answers to philosophical questions. The discovery of new methods has often had important consequences both for how philosophers conduct their research and for what claims they defend. [249] [239] [243] Some philosophers engage in most of their theorizing using one particular method while others employ a wider range of methods based on which one fits the specific problem investigated best. [250]

Conceptual analysis is a common method in analytic philosophy. It aims to clarify the meaning of concepts by analyzing them into their component parts. [251] [49] [252] Another method often employed in analytic philosophy is based on common sense. It starts with commonly accepted beliefs and tries to draw unexpected conclusions from them, which it often employs in a negative sense to criticize philosophical theories that are too far removed from how the average person sees the issue. [242] [253] [254] It is similar to how ordinary language philosophy approaches philosophical questions by investigating how ordinary language is used. [239] [255] [256]

The trolley problem is a thought experiment that investigates the moral difference between doing and allowing harm. This issue is explored in an imaginary situation in which a person can sacrifice a single person by redirecting a trolley in order to save a group of people. Trolley Problem.svg
The trolley problem is a thought experiment that investigates the moral difference between doing and allowing harm. This issue is explored in an imaginary situation in which a person can sacrifice a single person by redirecting a trolley in order to save a group of people.

Various methods in philosophy give particular importance to intuitions, that is, non-inferential impressions about the correctness of specific claims or general principles. [259] [260] For example, they play an important role in thought experiments, which employ counterfactual thinking to evaluate the possible consequences of an imagined situation. These anticipated consequences can then be used to confirm or refute philosophical theories. [261] [262] [263] The method of reflective equilibrium also employs intuitions. It seeks to form a coherent position on a certain issue by examining all the relevant beliefs and intuitions, some of which often have to be deemphasized or reformulated in order to arrive at a coherent perspective. [264] [265] [266]

Pragmatists stress the significance of concrete practical consequences for assessing whether a philosophical theory is true. [267] [268] According to the pragmatic maxim as formulated by Charles Sanders Peirce, the idea a person has of an object is nothing more than the totality of practical consequences they associate with this object. Pragmatists have also used this method to expose disagreements as merely verbal, that is, to show they make no genuine difference on the level of consequences. [269] [270]

Phenomenologists seek knowledge of the realm of appearance and the structure of human experience. They insist upon the first-personal character of all experience and proceed by suspending theoretical judgments about the external world. This technique of phenomenological reduction is known as "bracketing" or epoché. The goal is to give an unbiased description of the appearances of things. [271]

Relation to other fields

Philosophy is closely related to many other fields. It is sometimes understood as a metadiscipline that clarifies their nature and limits. It does this by critically examining their basic concepts, background assumptions, and methods. In this regard, it plays a key role in providing an interdisciplinary perspective. It bridges the gap between different disciplines by analyzing which concepts and problems they have in common. It shows how they overlap while also delimiting their scope. [272] Historically, philosophy is often considered the "mother of all sciences" since most of the individual sciences formed part of philosophy until they reached their status as autonomous disciplines. [7] [8]

The influence of philosophy is felt in various fields that require difficult practical decisions. In medicine, philosophical considerations related to bioethics affect issues like whether an embryo is already a person and under what conditions abortion is morally permissible. A closely related philosophical problem is how humans should treat other animals, for example, whether it is acceptable to use non-human animals as food or for research experiments. [273] [274] [275]

In relation to business and professional life, philosophy has contributed by providing ethical frameworks. They contain guidelines on which business practices are morally acceptable and cover the issue of corporate social responsibility. In the field of politics, philosophy addresses issues like how to assess whether a government policy is just. [276] [274]

Philosophical inquiry is relevant to many fields that are concerned with what to believe and how to arrive at evidence for one's beliefs. [277] This is a key issue for the sciences, which have as one of their prime objectives the creation of scientific knowledge. Scientific knowledge is based on empirical evidence but it is often not clear whether empirical observations are neutral or already include theoretical assumptions. A closely related problem is whether the available evidence is sufficient to decide between competing theories. [278] [279]

In the fields of theology and religion, there are many doctrines associated with the existence and nature of God as well as rules governing correct behavior. A key issue is whether a rational person should believe these doctrines, for example, whether revelation in the form of holy books and religious experiences of the divine are sufficient evidence for these beliefs. [280] [281] [282]

A similar epistemological problem in relation to the law is what counts as evidence and how much evidence is required to find a person guilty of a crime. A related issue in journalism is how to ensure truth and objectivity when reporting on events. [272]

Philosophy in the form of logic has been influential in the fields of mathematics and computer science. [283] [284] [285] Further fields influenced by philosophy include psychology, sociology, linguistics, education, and the arts. [286] The close relation between philosophy and other fields in the contemporary period is reflected in the fact that many philosophy graduates go on to work in related fields rather than in philosophy itself. [287]

Philosophical ideas have also prepared and shaped changes in the field of politics. For example, ideals formulated in Enlightenment philosophy laid the foundation for constitutional democracy and played a role in the American Revolution and the French Revolution. [288] Marxist philosophy and its exposition of communism was one of the factors in the Russian Revolution and the Chinese Communist Revolution. [289] [290] [291] In India, Mahatma Gandhi's philosophy of non-violence shaped the Indian independence movement. [292] [293]

An example of the cultural and critical role of philosophy is found in its influence on the feminist movement. It has shaped the understanding of key concepts in feminism, for instance, the meaning of gender, how it differs from biological sex, and what role it plays in the formation of personal identity. Philosophers have also investigated the concepts of justice and equality and their implications with respect to the prejudicial treatment of women in male-dominated societies. [294] [295] [296]

However, the idea that philosophy is useful for many aspects of life and society is sometimes rejected. According to one such view, philosophy is mainly done for its own sake and does not make significant contributions to existing practices or external goals. [297] [298] [299]

See also

Related Research Articles

<span class="mw-page-title-main">Avicenna</span> Persian polymath, physician and philosopher (c.980–1037)

Ibn Sina, commonly known in the West as Avicenna, was the preeminent philosopher and physician of the Muslim world, flourishing during the Islamic Golden Age, serving in the courts of various Iranian rulers. He is often described as the father of early modern medicine. His philosophy was of the Muslim Peripatetic school derived from Aristotelianism.

<span class="mw-page-title-main">Epistemology</span> Branch of philosophy concerning knowledge

Epistemology is the branch of philosophy concerned with knowledge. Contemporary philosophers consider it a major subfield of philosophy, along with ethics, logic, and metaphysics, which are more ancient subdivisions of philosophy. There are different views on the relation between epistemology, natural sciences and these ancient divisions of philosophy: William Alston considers that it has historically always been a part of cognitive psychology. Quine viewed epistemology as a chapter of psychologySect.1.1 whereas Russell viewed it as a mix of psychology and logic. In contrast, Popper, Carnap and others in the Vienna circle considered that only objective or intersubjective knowledge should be studied in epistemology.

<span class="mw-page-title-main">Existence</span> State of being real

Existence is the state of being real or participating in reality. It can refer both to individual entities and the world as a whole. The terms "being", "reality", and "actuality" are often used as close synonyms. Existence contrasts with nonexistence, nothingness, and nonbeing. A common distinction is between the existence of an entity and its essence, which refers to the entity's nature or essential qualities.

<span class="mw-page-title-main">Immanuel Kant</span> German philosopher (1724–1804)

Immanuel Kant was a German philosopher and one of the central Enlightenment thinkers. Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and aesthetics have made him one of the most influential and controversial figures in modern Western philosophy.

<span class="mw-page-title-main">Logical positivism</span> Movement in Western philosophy

Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement whose central thesis is the verification principle. This theory of knowledge asserted that only statements verifiable through direct observation or logical proof are meaningful in terms of conveying truth value, information or factual content. Starting in the late 1920s, groups of philosophers, scientists, and mathematicians formed the Berlin Circle and the Vienna Circle, which, in these two cities, would propound the ideas of logical positivism.

<span class="mw-page-title-main">Metaphilosophy</span> Investigation of the nature of philosophy

Metaphilosophy, sometimes called the philosophy of philosophy, is "the investigation of the nature of philosophy". Its subject matter includes the aims of philosophy, the boundaries of philosophy, and its methods. Thus, while philosophy characteristically inquires into the nature of being, the reality of objects, the possibility of knowledge, the nature of truth, and so on, metaphilosophy is the self-reflective inquiry into the nature, aims, and methods of the activity that makes these kinds of inquiries, by asking what is philosophy itself, what sorts of questions it should ask, how it might pose and answer them, and what it can achieve in doing so. It is considered by some to be a subject prior and preparatory to philosophy, while others see it as inherently a part of philosophy, or automatically a part of philosophy while others adopt some combination of these views.

<span class="mw-page-title-main">Metaphysics</span> Branch of philosophy dealing with reality

Metaphysics is the branch of philosophy that studies the fundamental nature of reality. This includes the first principles of: being or existence, identity, change, space and time, cause and effect, necessity, actuality, and possibility.

In its most common sense, philosophical methodology is the field of inquiry studying the methods used to do philosophy. But the term can also refer to the methods themselves. It may be understood in a wide sense as the general study of principles used for theory selection, or in a more narrow sense as the study of ways of conducting one's research and theorizing with the goal of acquiring philosophical knowledge. Philosophical methodology investigates both descriptive issues, such as which methods actually have been used by philosophers, and normative issues, such as which methods should be used or how to do good philosophy.

<span class="mw-page-title-main">Philosophy of science</span> Study of foundations, methods, and implications of science

Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultimate purpose of science. This discipline overlaps with metaphysics, ontology, and epistemology, for example, when it explores the relationship between science and truth. Philosophy of science focuses on metaphysical, epistemic and semantic aspects of science. Ethical issues such as bioethics and scientific misconduct are often considered ethics or science studies rather than the philosophy of science.

<span class="mw-page-title-main">Analytic philosophy</span> 20th-century tradition of Western philosophy

Analytic philosophy is a branch and tradition of philosophy using analysis, popular in the Western world and particularly the Anglosphere, which began around the turn of the 20th century in the contemporary era in the United Kingdom, United States, Canada, Australia, New Zealand, and Scandinavia, and continues today. Analytic philosophy is often contrasted with continental philosophy, coined as a catch-all term for other methods, prominent in Europe.

<span class="mw-page-title-main">Knowledge</span> Awareness of facts or being competent

Knowledge is a form of awareness or familiarity. It is often understood as awareness of facts or as practical skills, and may also mean familiarity with objects or situations. Knowledge of facts, also called propositional knowledge, is often defined as true belief that is distinct from opinion or guesswork by virtue of justification. While there is wide agreement among philosophers that propositional knowledge is a form of true belief, many controversies in philosophy focus on justification. This includes questions like whether justification is needed at all, how to understand it, and whether something else besides it is needed. These controversies intensified due to a series of thought experiments by Edmund Gettier and have provoked various alternative definitions. Some of them deny that justification is necessary and suggest alternative criteria. Others accept that justification is an essential aspect and formulate additional requirements.

Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and plays a role in various other fields, like epistemology and law.

<span class="mw-page-title-main">Indian philosophy</span> Philosophical traditions of the Indian subcontinent

Indian philosophy consists of philosophical traditions of the Indian subcontinent. A traditional Hindu classification divides āstika and nāstika schools of philosophy, depending on one of three alternate criteria: whether it believes the Vedas as a valid source of knowledge; whether the school believes in the premises of Brahman and Atman; and whether the school believes in afterlife and Devas.

<span class="mw-page-title-main">History of philosophy</span> Study of the development of philosophy

The history of philosophy is the systematic study of the development of philosophical thought. It focuses on philosophy as rational inquiry based on argumentation but some theorists also include myths, religious traditions, and proverbial lore.

<span class="mw-page-title-main">Outline of philosophy</span> Overview of and topical guide to philosophy

Philosophy is the study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language. It is distinguished from other ways of addressing fundamental questions by being critical and generally systematic and by its reliance on rational argument. It involves logical analysis of language and clarification of the meaning of words and concepts.

Metaphysical naturalism is a philosophical worldview which holds that there is nothing but natural elements, principles, and relations of the kind studied by the natural sciences. Methodological naturalism is a philosophical basis for science, for which metaphysical naturalism provides only one possible ontological foundation. Broadly, the corresponding theological perspective is religious naturalism or spiritual naturalism. More specifically, metaphysical naturalism rejects the supernatural concepts and explanations that are part of many religions.

Feminist philosophy is an approach to philosophy from a feminist perspective and also the employment of philosophical methods to feminist topics and questions. Feminist philosophy involves both reinterpreting philosophical texts and methods in order to supplement the feminist movement and attempts to criticise or re-evaluate the ideas of traditional philosophy from within a feminist framework.

<span class="mw-page-title-main">Quietism (philosophy)</span> View on the purpose of philosophy

Quietism in philosophy sees the role of philosophy as broadly therapeutic or remedial. Quietist philosophers believe that philosophy has no positive thesis to contribute, but rather that its value is in defusing confusions in the linguistic and conceptual frameworks of other subjects, including non-quietist philosophy. For quietists, advancing knowledge or settling debates is not the job of philosophy, rather philosophy should liberate the mind by diagnosing confusing concepts.

<span class="mw-page-title-main">Stoicism</span> Philosophical system

Stoicism is a school of Hellenistic philosophy that flourished in Ancient Greece and Ancient Rome. The Stoics believed that the practice of virtue is enough to achieve eudaimonia: a well-lived, flourishing life. The Stoics identified the path to achieving it with a life spent practicing certain virtues in everyday life such as courage or temperance and living in accordance with nature. It was founded in the ancient Agora of Athens by Zeno of Citium around 300 BC.

<span class="mw-page-title-main">Logic</span> Study of correct reasoning

Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or logical truths. It studies how conclusions follow from premises due to the structure of arguments alone, independent of their topic and content. Informal logic is associated with informal fallacies, critical thinking, and argumentation theory. It examines arguments expressed in natural language while formal logic uses formal language. When used as a countable noun, the term "a logic" refers to a logical formal system that articulates a proof system. Logic plays a central role in many fields, such as philosophy, mathematics, computer science, and linguistics.



  1. These dates are traditionally cited but some recent scholars suggest that his life ran from 1077 to 1157. [110]
  2. The truth conditions of a sentence are the circumstances or states of affairs under which the sentence would be true. [205]


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