77 Branches of Philosophy

The core divisions

Aesthetics The study of beauty, art and taste. It began as an enquiry into a kind of experience and became an argument about what qualifies as art at all. 1750 Axiology The general study of value, of which ethics and aesthetics are both special cases. The least known of the core divisions and the one they both depend on. early 20th century Epistemology The study of knowledge itself — what it is, how it is acquired, how much of it we have, and whether any of it is secure. Every other branch depends on some answer to it, which is why it has been contested for as long as philosophy has existed. 1854 Ethics The study of how to act and what kind of person to be. The oldest question in the subject, and the one non-philosophers are most surprised to find unsettled. Logic The study of what follows from what. The only branch of philosophy that became a formal science, and the one that gave computing its foundations. Metaphysics The study of what exists and what existence is. Every other branch borrows an answer from it, and none of them can settle one. c. 60 BCE Political Philosophy The study of authority, justice and the state. It asks not how power is held but whether holding it can ever be justified.

Within the core divisions

Applied Ethics Moral philosophy on real problems - in medicine, war, business and research. It was treated as the field's practical afterthought and is now where most of its work happens. Decision Theory The formal study of choice under uncertainty. Its central theorem is elegant, widely used, and contradicted by how careful people actually choose. Formal Logic Logic done as mathematics. It answered the question of its own limits more precisely than any other branch has ever answered anything, and the answer was that limits exist. Free Will and Determinism The problem of whether choice survives causation. Almost everything we do about blame, punishment and desert assumes an answer, and no answer commands agreement. Informal Logic and Argumentation The study of reasoning as it is actually conducted - in courtrooms, editorials and disagreements - where premises go unspoken and conclusions are matters of degree. Metaethics Not which acts are right, but what a claim about rightness is and whether it can be true. The question underneath ethics, and the one that can be answered without settling any moral dispute. Moral Psychology The study of moral judgement, motivation and character as they actually work. The one part of ethics where empirical findings bear directly on philosophical positions. Normative Ethics The attempt to state, in general terms, what makes right acts right. Three families of theory have been in contention for two centuries and none has driven out the others. Ontology The inventory branch of metaphysics: not whether a particular thing exists, but what categories of thing there are and what commits you to them. 1606 Personal Identity The question of what you are and what would end you. Every answer given has a case it cannot handle, and one influential line holds that the question matters less than it seems to. Philosophy of Causation The study of the relation everything else relies on. Science, law and ordinary explanation all rest on causation, and no analysis of it has survived its counterexamples. Philosophy of Nature The study of nature as such - what a law of nature is, what a natural kind is, and whether calling something natural says anything about it. Philosophy of Probability The study of what a probability is. The mathematics has been settled for ninety years and there is still no agreement about what the numbers refer to. Philosophy of Space and Time The oldest dispute in metaphysics that physics has actually joined: whether space and time are a container the world sits in, or a pattern the world makes. Social Epistemology Epistemology done with the observation that almost nothing anyone knows was worked out by them. It treats knowing as something communities do.

Mind and language

Philosophy of Action The study of intention and agency. It asks what separates raising your arm from your arm going up, and finds that the difference is remarkably hard to state. Philosophy of Cognitive Science The philosophy of the interdisciplinary study of cognition. Its founding idea was that thought is computation over representations, and its most interesting recent work challenges both halves of that. Philosophy of Emotion The study of what emotions are and whether they can be right or wrong. For most of the tradition they were treated as interference; the modern field treats them as a form of appraisal. Philosophy of Language The study of meaning, reference and communication. For much of the twentieth century it was not one branch among others but the method philosophy was conducted by. Philosophy of Mind The study of consciousness, thought and the relation between mind and body. The one place where the thing being investigated is also the thing investigating. Philosophy of Perception The study of what perception delivers. It begins from the observation that seeing seems to put us in contact with the world, and that illusions seem to show otherwise. Philosophy of Psychology The philosophy of a particular science, and of an unusually difficult one: psychology's objects cannot be observed directly and its categories are partly of its own making.

Science and formal enquiry

Philosophy of Biology The philosophy of the science that broke the model. Biology has no laws like physics, its central categories are contested, and it is the one science that explains by what things are for. Philosophy of Chemistry The philosophy of the science everyone assumed had been absorbed by physics. It had not, and working out why has made it the best case study in what reduction actually means. Philosophy of Mathematics The most certain body of knowledge anyone has, about objects nobody can locate. Every account of what makes it true has trouble explaining how we could find out. Philosophy of Medicine The philosophy of a practice as much as a science. Its central question is whether disease is a fact about bodies or a judgement about which states are bad. Philosophy of Physics The branch where philosophy is done inside a science. Quantum mechanics predicts perfectly and nobody agrees what it describes, and that gap is this field's subject. Philosophy of Psychiatry The branch where the concept of disease is hardest to hold and matters most. Its categories carry legal and social consequences that no other medical classification does. Philosophy of Science Science is the most successful knowledge-producing enterprise there has ever been, and there is still no agreed account of what it is or why it works. This branch is the attempt to give one. Philosophy of the Social Sciences The philosophy of the sciences whose subject matter answers back. Their objects have views about the categories used to describe them, and change in response to being described.

Technology and computation

Ethics of Artificial Intelligence Applied ethics on systems that act, are not agents, and are built by many hands. The novel problem is not that machines might be moral but that responsibility has nowhere obvious to land. Philosophy of Computing The philosophy of an activity that is half mathematics and half engineering. Its central puzzle is that a program is an abstract object that has to actually work. Philosophy of Information A field built on a word that carries at least three unrelated technical meanings. Sorting them out turns out to bear on knowledge, biology and physics at once. Philosophy of Technology The study of what technology is and what it does to those who use it. Its founding question is whether a tool is neutral, and its founding answer is that it is not.

Society, politics and law

Philosophical Anthropology The attempt to say what humans are, as a whole, rather than in parts. It was a major twentieth-century project, was declared impossible, and keeps being needed. Philosophy of Democracy The examination of the assumption almost nobody examines. Democracy's justification is contested even among people who are certain it is the right arrangement. Philosophy of Economics The philosophy of a discipline that claims to be descriptive, is built on assumptions about rationality, and produces recommendations governments act on. Philosophy of Education The study of what education is for and who decides. Every society answers it in practice, mostly without noticing that a contested question has been settled. Philosophy of History Two questions under one name: whether history is going anywhere, and what historians are doing when they explain. The first is largely abandoned; the second is very much alive. Philosophy of Law The study of what law is and whether it must be just to count. The question was academic until courts had to decide whether the statutes of a criminal regime had ever been law at all. Philosophy of War and Peace The attempt to apply moral limits to the activity least inclined to accept them. Its framework is old, is embedded in international law, and is under its most serious challenge in centuries. Social Philosophy The study of social reality itself - money, marriage, universities, classes, norms - all of which are real, none of which would exist if people stopped treating them as real.

Identity and justice

Feminist Philosophy Not a branch about women but a body of work reaching into every branch, on the grounds that a discipline built almost entirely by men made assumptions it never noticed making. Philosophy of Disability The branch that reframed its own subject. Its central move was to locate disability in the fit between a person and an environment rather than in the person alone. Philosophy of Gender A branch whose central question is contested inside philosophy and outside it. What follows sets out the positions rather than adjudicating between them. Philosophy of Human Rights The examination of the most widely invoked moral idea of the last century. Its practical authority is enormous and its philosophical foundations are genuinely disputed. Philosophy of Race A branch whose central object may not exist. Race has no biological basis and enormous social reality, and holding both of those together is the field's whole difficulty.

Life and environment

Animal Ethics The field that asks why species membership should matter morally. Its central argument is short, hard to refute, and almost universally ignored in practice. Bioethics The best-established branch of applied ethics, built out of medical scandal and new technology. Its working framework was designed to be usable by committees rather than to be theoretically correct. Environmental Philosophy The branch that asks whether anything without a mind can be wronged. Its founding thought experiment is one sentence long and has never been comfortably answered.

Religion

Philosophical Theology Philosophy done inside a tradition rather than about it. It takes doctrines as given and asks whether they can be made coherent, which is a real question with real failures. Philosophy of Religion The examination of religious claims by argument rather than by faith or by history. It is done by believers and unbelievers alike, and the arguments do not sort by conviction.

Art and culture

Philosophy of Art The philosophy of made things offered as art. Every definition proposed has been defeated by an actual artwork, which is unusual and tells you something about the subject. Philosophy of Film The philosophy of the art made by a machine. Its distinctive question is whether a photograph puts us in contact with what it shows, or merely represents it. Philosophy of Literature The philosophy of writing that is not trying to state facts. Its central puzzle is that readers weep over characters they know perfectly well are invented. Philosophy of Music The philosophy of the art that represents nothing and moves people most reliably. Its central problem is that music is expressive without expressing anything in particular. Philosophy of Sport The philosophy of activities whose entire point is to make something harder than it needs to be. The definition of a game it produced is one of philosophy's cleanest results.

Meta and method

Comparative Philosophy The study of philosophy across traditions, and of whether such comparison is possible without distortion. Its hardest problem is that comparison needs a common measure and there may not be one. History of Philosophy Reading the dead well. The discipline's methodological question is whether we are looking for allies in current arguments or for what someone actually meant. Metaphilosophy Philosophy examining itself. The uncomfortable question it cannot avoid is why, after two and a half thousand years, so few of its questions are settled.

Outside the Western scheme

Abhidharma Buddhist systematic analysis: an inventory of what ultimately exists, built to show that persons are not among the ultimate constituents while remaining fully real as conventions. Alaṅkāraśāstra Indian literary theory, and one of the most sophisticated bodies of aesthetics produced anywhere. It answered the paradox of tragedy independently and, on some readings, better. Correlative cosmology The Chinese framework organising the world by pattern and resonance rather than by cause. It structured medicine, music, calendar and government for two thousand years and is not a theory of causation at all. Dharmaśāstra The Indian science of dharma - a body of reasoning about right conduct in which the answer depends on the agent's position, and in which sources of authority must be reconciled. c. 2nd century BCE Jingshi Chinese political thought conducted as practical administration. Its central dispute - whether to govern by virtue and ritual or by law and technique - ran for two thousand years and was tested empirically. Kalām Islamic rational theology - argument about God, creation, freedom and justice conducted by debate rather than by citation. Its atomism and occasionalism are among the boldest metaphysics anywhere. Mokṣa The Indian enquiry into liberation. Nearly every school defines itself by what it takes bondage to be, and their disagreements about that are disagreements about what a person is. Pramāṇa The Indian enquiry into the instruments of knowledge — perception, inference, comparison, testimony and others — and into how many of them there are. It is the closest thing in Indian philosophy to epistemology, and it is not the same subject. c. 2nd century CE Uṣūl al-fiqh Islamic legal theory: a fully developed jurisprudence of interpretation, worked out centuries before the European philosophy of law and organised around a different problem. Xiushen The Chinese enquiry into self-cultivation. It asks not what is right but how a person becomes the sort who does it, and treats that as the primary question rather than a follow-up.