''Philosophy'' is the critical study of the most fundamental questions that humankind has been able to ask. Philosophers ask questions such as
* Metaphysics: What is the nature of things that exist? ''Are'' there things in a natural world independent of our perception? What does it mean to think, to have a mind? Is there a god?
* Epistemology: Is knowledge possible, and if so, what is knowledge? How can we know that other minds (i.e. other thinking beings) actually exist?
* Ethics: Is there a difference between right and wrong, and if so, how can we prove this? What should I do? How should I live?
Philosophy is paradigmatically concerned with fundamental concepts such as Existence or Being (Metaphysics), Rightness or Goodness (Ethics), Knowledge (Epistemology), Truth (Logic) and Beauty (Aesthetics); philosophers have often been particularly concerned with asking critical questions about the natures of these concepts; questions which don't seem to be amenable to treatment by the special sciences.
__The philosophical method__
Philosophy is, perhaps, most clearly distinguished by the ''methods'' that it uses to grapple with the questions that philosophers pose. Philosophers generally frame problems in a logical manner, and then work towards a solution based on logical processes and reasoning, based on a critical reading and response to previous work in this area. This series of responses and counter-responses is a dialectical process.
It's a matter of considerable philosophical debate whether ''solving'' a philosophical problem is like answering a question in the natural sciences: whether or not, for example, philosophical ''solutions'' are definitive, and whether they tell you something informative about the structure of reality, or just get you more clear on the logic of our language. Closely connected to these debates about philosophical method are debates over the relationship between philosophy and natural science, and arguments over whether philosophy makes (or ''can'' make) progress in the same way that the natural sciences do. There is, indeed, an entire field of philosophy which is concerned with the nature of philosophical problems, philosophical solutions, and the proper method for getting from one to another: it is Meta-Philosophy, or (as it were) the philosophy of philosophy. The fact that such debates have their own specialized field does not mean that they are any less relevant to philosophy as a whole: the nature and role of philosophy itself has ''always'' been an essential part of the philosophical project, from the ancient Greeks onward. But it does mean that it is a lengthy debate beyond the scope of this article; and so such questions are discussed elsewhere.
__Non-academic uses of the word__
Popularly, the word ''philosophy'' is often used to mean any form of wisdom, or any person's perspective on life (as in ''philosophy of life'') or basic principles behind or method of achieving something (as in ''my philosophy about driving on highways'').
For example, reacting to a tragedy ''philosophically'' might mean abstaining from passionate reactions in favor of intellectualized detachment. That particular definition arose from the example of Socrates, who calmly discussed the nature of the soul with his followers while the hemlock took effect. The Stoics and other schools of philosophy in the ancient world saw themselves as Socratic in this sense. But the use of ''philosophically'' in this adverbial sense is only a rather distant relation of the contemporary academic usage.
This article, however, focuses specifically on philosophy as an academic discipline rather than these usages.
__Western and Eastern Philosophy__
Members of many societies around the world have considered the same questions, and built philosophic traditions based upon each other's works. Philosophy may be broadly divided into various realms based loosely on geography. The term ''philosophy'' alone in a Euro-American academic context usually refers to the philosophic traditions of Western civilization, sometimes also called Western philosophy. In the West, the term ''Eastern Philosophy'' broadly subsumes the philosophic traditions of Asia and the East.
The Western philosophic tradition began with the Greeks and continues to the present day. Famous Western philosophers include Plato, Aristotle, Thomas Aquinas, RenÃ© Descartes, John Locke, David Hume, Immanuel Kant, Georg Wilhelm Friedrich Hegel, Friedrich Nietzsche, Gottlob Frege, Bertrand Russell, Ludwig Wittgenstein, and W. V. Quine .
Famous Eastern philosophers include Gautama Buddha, Bodhidharma, Lao Zi (Lao Tzu), Confucius, and Zhuang Zi (Chuang Tzu). This article deals primarily with the Western philosophic tradition; for more information on Eastern philosophies, see Eastern Philosophy.
The word ''philosophy'' is derived from the ancient Greek ''philosophia'', literally meaning the love of wisdom (''philein'' = ''to love'' ''sophia'' = wisdom, in the sense of theoretical or cosmic insight). Etymology is not necessarily meaning, but the ancient Greeks seem to have thought of it mainly as an over-arching activity, or approach to life, rather than some specific set of academic questions.
The introduction of the terms ''philosopher'' and ''philosophy'' was ascribed to the Greek thinker Pythagoras: ''De vita et moribus philosophorum'', I, 12; Cicero: ''Tusculanae disputationes'', V, 8-9). The ascription is certainly based on a passage in a lost work of Herakleides Pontikos, a disciple of Aristotle. It is considered to be part of the widespread Pythagoras legends of this time. In fact the term ''philosophy'' was not in use long before Plato.
''Philosopher'' replaced the word ''sophist'' (from ''sophoi''), which was used to describe ''wise men,'' teachers of Rhetoric, who were important in Athenian democracy. Some of the most famous ''sophists'' were what we would now call philosophers, but Plato's dialogues often used the two terms to contrast those who are devoted to wisdom (philosophers) from those who arrogantly claim to have it (sophists). Socrates (at least, as portrayed by Plato) frequently characterized the sophists as incompetents or charlatans, who hid their ignorance behind word play and flattery, and so convinced others of what was baseless or untrue. To this day, ''sophist'' is often used as a derogatory term for one who merely persuades rather than reasons.
The scope of philosophy in the ancient understanding, and the writings of (at least some of) the ancient philosophers, was ''all'' intellectual endeavors. This included the problems of philosophy as they are understood today; but it also included many other disciplines, such as pure mathematics and Natural Sciences such as physics, astronomy, and biology. (Aristotle, for example, wrote on all of these topics; as late as the 17th century physics, astronomy, and biology were still referred to as branches of ''natural philosophy''). Over time, academic specialization and the rapid technical advance of the special sciences led to the development of distinct disciplines for these sciences, and their separation from philosophy: mathematics became a specialized science in the ancient world, and ''natural philosophy'' developed into the disciplines of the natural sciences over the course of the Scientific Revolution. Today, philosophical questions are usually explicitly distinguished from the questions of the special sciences, and characterized by the fact that (unlike those of the sciences) they are the sort of questions which are foundational and abstract in nature, and which are not amenable to being answered by experimental means.
Philosophical inquiry is often divided into several major ''branches'' based on the questions typically addressed by people working in different parts of the field. In the ancient world, the most influential division of the subject was the Stoics' division of philosophy into Logic, Ethics, and ''Physics'' (conceived as the study of the nature of the world, and including both Natural Science and Metaphysics). In contemporary philosophy, specialties within the field are more commonly divided into Metaphysics, Epistemology, Ethics and Aesthetics (which together comprise Axiology). Logic is sometimes included as another main branch of philosophy, sometimes as a separate science which philosophers often happen to work on, and sometimes just as a characteristically philosophical method applying to all branches of philosophy.
Within these broad branches there are numerous sub-disciplines of philosophy. The interest in particular sub-disciplines waxes and wanes over time; sometimes sub-disciplines become particularly hot topics and can occupy so much space in the literature that they almost seem like major branches in their own right. (Over the past 40 years or so philosophy of mind — which is, strictly speaking, mainly a sub-discipline of Metaphysics — has taken on this position within Analytic Philosophy. It has attracted so much attention that some suggest philosophy of mind as ''the'' paradigm for what contemporary Analytic philosophers do.)
Some of the many sub-disciplines within philosophy include:
*Axiology: the branch of philosophical enquiry that explores:
**Aesthetics: the study of basic philosophical questions about Art and Beauty. Sometimes Philosophy of Art is used to describe only questions about art, while ''aesthetics'' is the more general term. Likewise ''aesthetics'' sometimes applies more broadly than to merely the ''philosophy of beauty'': to include the sublime, humour, or fright - to any of the responses we might expect works of art or entertainment to elicit.
**Ethics: the study of what makes actions right or wrong, and of how theories of right action can be applied to special moral problems. Subdisciplines include Meta-Ethics, Value Theory, Theory of Conduct, and Applied Ethics.
*Epistemology: the study of knowledge and its nature, possibility, and justification.
*History of Philosophy: the study of what philosophers up until recent times have written, its interpretation, who influenced whom, and so forth. History of philosophy can be approached either ''exegetically'' (in which case the main question is the interpretive question of what past philosophers mean and how the structure of their thought holds together) or ''critically'' (in which case the main question is the logical question of whether what past philosophers said was true or false, and what the philosophical consequences of their views are).
*Logic: the study of the standards of correct argumentation. The characteristic method of this study is the development of Formal Logic to symbolize and evaluate arguments; the characteristic topic is propositional logic, the logic of simple indicative statements. (Classical logic focused on a narrower subset: categorical reasoning by syllogism.) The more advanced topics in logic are generally extensions of formal logic to symbolize the logical relationships involved in particular aspects of the language -- such as Modal Logic, which deals with modal qualifiers like ''possibly'' and ''necessarily'', or Temporal Logic, which deals with the logical relationships established by the ''tense'' of a sentence.
*Meta-Philosophy: the study of Philosophical Method and the nature and purpose of philosophy. The term ''philosophy of philosophy'' is sometimes used more or less as a synonym.
*Metaphysics (which includes Ontology): the study of the most basic categories of things, such as existence, objects, properties, causality, and so forth. Metaphysics often is taken to include questions now studied by other philosophical subdisciplines, such as the Mind-Body Problem and Free Will and Determinism.
*Philosophy of Biology: the philosophical study of some basic concepts of biology, including the notion of a species and whether biological concepts are reducible to nonbiological concepts.
*Philosophy of Education: the study of the purpose and most basic methods of education or learning.
*Philosophy of History: the study of the methods by which history is derived and accepted.
*Philosophy of Language: the study of the concepts of Meaning and Truth.
*Philosophy of Mathematics: the study of philosophical questions raised by mathematics, such as, what numbers are, and what the nature and origins of our mathematical knowledge are.
*philosophy of mind: the philosophical study of the nature of the mind, and its relation to the body and the rest of the world.
*Philosophy of Perception: the philosophical study of topics related to perception; the question what the ''immediate objects'' of perception are has been especially important.
*Philosophy of Physics: the philosophical study of some basic concepts of physics, including space, time, and force.
*Philosophy of Psychology: the study of some fundamental questions about the methods and concepts of psychology and psychiatry, such as the meaningfulness of Freudian concepts; this is sometimes treated as including philosophy of mind.
*Philosophy of Science: includes not only, as subdisciplines, the ''philosophies of'' the special sciences (i.e., physics, biology, etc.), but also questions about induction, Scientific Method, scientific progress, etc.
*Philosophy of Social Sciences: the philosophical study of some basic concepts, methods, and presuppositions of social sciences such as sociology and economics.
*Political Philosophy: the study of basic topics concerning government, including the purpose of the state, political justice, political freedom, the nature of law, the administration of justice and paternalism.
* Value Theory: the study of the concept value. Also called ''theory of value''. Sometimes this is taken to be equivalent to Axiology (a term not in as much currency in the English-speaking world as it once was), and sometimes is taken to be, instead of a foundational field, an overarching field including ethics, aesthetics, and political philosophy, i.e., the philosophical subdisciplines that crucially depend on questions of value.
__How to get started in philosophy__
It is a platitude (at least among people who write introductions to philosophy) that everybody has a philosophy, though they might not all realize it or be able to defend it. But at the same time the word ''philosophy'' as it is used by philosophers is nothing like what is meant by people who say ''Here's my philosophy (of life, etc.): . . .'' Such is the tension between pedagogy and scholarship.
If you're already interested in studying philosophy, your reason might be to improve the way you live or think somehow, or you simply wish to get acquainted with one of the most ancient areas of human thought. On the other hand, if you don't see what all the fuss is about, it might help to read the motivation to philosophize, which explains what motivates many people to ''do philosophy,'' and get an ''introduction to philosophical method'', which is important to understanding how philosophers think. It might also help to acquaint yourself with some considerations about just what philosophy is.
Philosophy has applications. The most obvious applications are those in Ethics--Applied Ethics in particular--and in Political Philosophy. The political philosophies of John Locke, Jean-Jacques Rousseau, Karl Marx, John Stuart Mill, and John Rawls have shaped and been used to justify governments and their actions. Philosophy of Education deserves special mention, as well; progressive education as championed by John Dewey has had a profound impact on educational practices in the United States in the twentieth century.
Other important, but less immediate applications can be found in Epistemology, which might help one to regulate one's notions of what knowledge, evidence, and justified belief are. Philosophy of Science discusses the underpinnings of the Scientific Method, among other topics sometimes useful to scientists. Aesthetics can help to interpret discussions of art. Even Ontology, surely the most abstract and least practical-seeming branch of philosophy, has had important consequences for Logic and computer science. In general, the various ''philosophies of,'' such as Philosophy of Law, can provide workers in their respective fields with a deeper understanding of the theoretical or conceptual underpinnings of their fields.
Moreover, recently, there has been developing a burgeoning profession devoted to applying philosophy to the problems of ordinary life: Philosophical Counseling.
__Philosophy contrasted with other disciplines__
Originally the term ''philosophy'' was applied to ''all'' intellectual endeavour. Aristotle studied what would now be called biology, meteorology, physics, and cosmology, alongside his metaphysics and ethics. Even in the eighteenth century physics and chemistry were still classified as ''natural philosophy'', that is, the philosophical study of nature. Today these latter subjects are referred to as Science.
Psychology, economics, sociology, and linguistics were once the domain of philosophers insofar as they were studied at all, but now have only a weaker connection with the field. In the late twentieth century cognitive science and artificial intelligence could be seen as being forged in part out of ''philosophy of mind.''
Philosophy is done a priori. It does not and cannot rely on experiment. However, in some ways philosophy is close to science in its character and method; some Analytic philosophers have suggested that the method of philosophical analysis allows philosophers to emulate the methods of natural science; W. V. Quine holds that philosophy just is a branch of natural science, simply the most abstract one. This approach, now common, is called ''philosophical naturalism''.
Philosophers have always devoted some study to science and the scientific method, and to logic, and this involves, indirectly, studying the subject matters of those sciences. Whether philosophy also has its own, distinct subject matter is a contentious point. Traditionally Ethics, Aesthetics, and Metaphysics have all been philosophical subjects, but many philosophers have, especially in the twentieth century, rejected these as futile questions (the ''Vienna Circle''). Philosophy has also concerned itself with explaining the foundations and character knowledge in general (of science, or history), and in this case it would be a sort of ''science of science'' but some now hold that this cannot consist in any more than clarifying the arguments and claims of other sciences. This suggests that philosophy might be the study of meaning and reasoning generally; but some still would claim either that this is not a science, or that if it is it ought not to be pursued by philosophers.
All these views have something in common: whatever philosophy essentially is or is concerned with, it tends on the whole to proceed more ''abstractly'' than most (or most other) natural sciences. It does not depend as much on experience and experiment, and does not contribute as directly to technology. It clearly would be a mistake to identify philosophy with any one natural science; whether it can be identified with science very broadly construed is still an open question.
__Philosophy of Science__
This is an active discipline pursued by both trained philosophers and scientists. Philosophers often ''refer to'', and interpret, experimental work of various kinds (as in philosophy of physics and philosophy of psychology). But this is not surprising: such branches of philosophy aim at philosophical understanding ''of'' experimental work. It is not the philosophers in their capacity ''as'' philosophers, who perform the experiments and formulate the scientific theories under study. Philosophy of science should not be confused with science it studies any more than biology should be confused with plants and animals.
__Theology and Religious studies__
Like philosophy, most religious studies are not experimental. Parts of theology, including questions about the existence and nature of gods, clearly overlap with Philosophy of Religion. Aristotle considered Theology a branch of Metaphysics, the central field of philosophy, and most philosophers prior to the twentieth century have devoted significant effort to theological questions. So the two are not unrelated. But other part of religious studies, such as the comparison of different world religions, can be easily distinguished from philosophy in just the way that any other social science can be distinguished from philosophy. These are closer to history and sociology, and involve specific observations of particular phenomena, here particular religious practices.
Nowadays religion plays a very marginal role in philosophy. The Empiricist tradition in modern philosophy often held that religious questions are beyond the scope of human knowledge, and many have claimed that religious language is literally meaningless: there are not even questions to be answered. Some philosophers have felt that these difficulties in evidence were irrelevant, and have argued for, against, or just about religious beliefs on moral or other grounds. Nonetheless, in the main stream of twentieth century philosophy there are very few philosophers who give serious consideration to religious questions.
Mathematics uses very specific, rigorous methods of proof that philosophers sometimes (only rarely) try to emulate. Most philosophy is written in ordinary prose, and while it strives to be precise it does not usually attain anything like mathematical clarity. As a result, mathematicians hardly ever disagree about results, while philosophers of course do disagree about their results, as well as their methods.
The Philosophy of Mathematics is a branch of Philosophy of Science; but in many ways mathematics has a special relationship to philosophy. This is because the study of Logic is a central branch of philosophy, and mathematics is a paradigm example of logic. In the late nineteenth and twentieth centuries logic made great advances, and mathematics has been proven to be reducible to logic (at least, to first-order logic with some Set Theory). The use of formal, mathematical logic in philosophy now resembles the use of math in science, although it is not as frequent.
__Some tentative generalizations about what philosophy is__
So philosophy, it seems, is a discipline that draws on knowledge that the average educated person has, and it does not make use of experimentation and careful observation, though it may interpret philosophical aspects of experiment and observation.
More positively, one might say that philosophy is a discipline that examines the meaning and justification of certain of our most basic, fundamental beliefs, according to a Philosophical Method. But what we might mean by the words ''basic, fundamental beliefs''?
A belief is fundamental if it concerns those aspects of the universe which are ''most commonly'' found, which are found everywhere: the ''universal'' aspects of things. Philosophy studies, for example, what ''existence itself'' is. It also studies value--the goodness of things--in general. Surely in human life we find the relevance of value or goodness everywhere, not just moral goodness, though that might be very important, but even more generally, goodness in the sense of anything that is actually desirable, the sense, for example, in which an apple, a painting, and a person can ''all'' be good. (If indeed there is a single sense in which they are all called ''good.'')
Of course, physics and the other sciences study some very universal aspects of things; but it does so experimentally. Philosophy studies those aspects that can be studied without experimentation. Those are aspects of things that are very general indeed; to take yet another example, philosophers ask what physical objects as such are, as distinguished from properties of objects and relations between objects, and perhaps also as distinguished from minds or souls. Physicists proceed as though the notion of a physical body is quite clear and straightforward--which perhaps in the end it will found to be--but at any rate, physics ''assumes'' that, and then asks questions about how all physical bodies behave, and then does experiments to find out the answers.
''Science is what we know and philosophy is what we don't know.'' - Bertrand Russell
''What is your aim in philosophy? To show the fly the way out of the fly-bottle.'' - Ludwig Wittgenstein
''Philosophy, n. A route of many roads leading from nowhere to nothing.'' - Ambrose Bierce