Origins
The introduction of the terms "philosopher" and "philosophy" has been ascribed to the Greek thinker Pythagoras (see Diogenes Laertius: "De vita et moribus philosophorum", I, 12; Cicero: "Tusculanae disputationes", V, 8-9). The ascription is based on a passage in a lost work of Herakleides Pontikos, a disciple of Aristotle. It is considered to be part of the widespread legends of Pythagoras of this time.
"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. Moreover, the sophists were paid for their explorations. 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; and as late as the 17th century, these fields 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.
Western Philosophical subdisciplines
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, and 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; the interpretation of such philosophers; who influenced whom, and so forth. The 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 the narrower subset of 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, objectss, 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 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 within human languages.
- Philosophy of mathematics: the study of philosophical questions raised by mathematics, such as the nature of numbers, 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 religion: the study of the meaning of the concept of God and of the rationality or otherwise of belief in the existence of God.
- 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.
