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. 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, with "aesthetics" the more general term. Likewise "aesthetics" sometimes applied even more broadly than to "philosophy of beauty" :to the "sublime," to humour, to the frightening--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, 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 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. Also see biosophy.
- 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 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.