Branches of philosophy

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.

These divisions are neither exhaustive, nor mutually exclusive. (A philosopher might specialize in Kantian epistemology, or Platonic aesthetics, or modern political philosophy). Furthermore, these philosophical inquiries sometimes overlap with each other and with other inquiries such as science, religion or mathematics.

Aesthetics

Aesthetics is the "critical reflection on art, culture and nature." It addresses the nature of art, beauty and taste, enjoyment, emotional values, perception and with the creation and appreciation of beauty. It is more precisely defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste. Its major divisions are art theory, literary theory, film theory and music theory. An example from art theory is to discern the set of principles underlying the work of a particular artist or artistic movement such as the Cubist aesthetic.

Ethics

Ethics, also known as moral philosophy, studies what constitutes good and bad conduct, right and wrong values, and good and evil. Its primary investigations include how to live a good life and identifying standards of morality. It also includes investigating whether or not there is a best way to live or a universal moral standard, and if so, how we come to learn about it. The main branches of ethics are normative ethics, meta-ethics and applied ethics.

The three main views in ethics about what constitute moral actions are:

• Consequentialism, which judges actions based on their consequences. One such view is utilitarianism, which judges actions based on the net happiness (or pleasure) and/or lack of suffering (or pain) that they produce.
• Deontology, which judges actions based on whether or not they are in accordance with one's moral duty. In the standard form defended by Immanuel Kant, deontology is concerned with whether or not a choice respects the moral agency of other people, regardless of its consequences.
• Virtue ethics, which judges actions based on the moral character of the agent who performs them and whether they conform to what an ideally virtuous agent would do.

Epistemology

Epistemology is the branch of philosophy that studies knowledge. Epistemologists examine putative sources of knowledge, including perceptual experience, reason, memory, and testimony. They also investigate questions about the nature of truth, belief, justification, and rationality.

Philosophical skepticism, which raises doubts about some or all claims to knowledge, has been a topic of interest throughout the history of philosophy. It arose early in Pre-Socratic philosophy and became formalized with Pyrrho, the founder of the earliest Western school of philosophical skepticism. It features prominently in the works of modern philosophers René Descartes and David Hume, and has remained a central topic in contemporary epistemological debates.

One of the most notable epistemological debates is between empiricism and rationalism. Empiricism places emphasis on observational evidence via sensory experience as the source of knowledge. Empiricism is associated with a posteriori knowledge, which is obtained through experience (such as scientific knowledge). Rationalism places emphasis on reason as a source of knowledge. Rationalism is associated with a priori knowledge, which is independent of experience (such as logic and mathematics).

One central debate in contemporary epistemology is about the conditions required for a belief to constitute knowledge, which might include truth and justification. This debate was largely the result of attempts to solve the Gettier problem. Another common subject of contemporary debates is the regress problem, which occurs when trying to offer proof or justification for any belief, statement, or proposition. The problem is that whatever the source of justification may be, that source must either be without justification (in which case it must be treated as an arbitrary foundation for belief), or it must have some further justification (in which case justification must either be the result of circular reasoning, as in coherentism, or the result of an infinite regress, as in infinitism).

Metaphysics

Metaphysics is the study of the most general features of reality, such as existence, time, objects and their properties, wholes and their parts, events, processes and causation and the relationship between mind and body. Metaphysics includes cosmology, the study of the world in its entirety and ontology, the study of being.

A major point of debate is between realism, which holds that there are entities that exist independently of their mental perception and idealism, which holds that reality is mentally constructed or otherwise immaterial. Metaphysics deals with the topic of identity. Essence is the set of attributes that make an object what it fundamentally is and without which it loses its identity while accident is a property that the object has, without which the object can still retain its identity. Particulars are objects that are said to exist in space and time, as opposed to abstract objects, such as numbers, and universals, which are properties held by multiple particulars, such as redness or a gender. The type of existence, if any, of universals and abstract objects is an issue of debate.

Logic

Logic is the study of reasoning and argument.

Deductive reasoning is when, given certain premises, conclusions are unavoidably implied. Rules of inference are used to infer conclusions such as, modus ponens, where given “A” and “If A then B”, then “B” must be concluded.

Because sound reasoning is an essential element of all sciences, social sciences and humanities disciplines, logic became a formal science. Sub-fields include mathematical logic, philosophical logic, Modal logic, computational logic and non-classical logics. A major question in the philosophy of mathematics is whether mathematical entities are objective and discovered, called mathematical realism, or invented, called mathematical antirealism.

Other subfields

Mind and language

Philosophy of language explores the nature, origins, and use of language. Philosophy of mind explores the nature of the mind and its relationship to the body, as typified by disputes between materialism and dualism. In recent years, this branch has become related to cognitive science.

Philosophy of science

The philosophy of science explores the foundations, methods, history, implications and purpose of science. Many of its subdivisions correspond to specific branches of science. For example, philosophy of biology deals specifically with the metaphysical, epistemological and ethical issues in the biomedical and life sciences.

Political philosophy

Political philosophy is the study of government and the relationship of individuals (or families and clans) to communities including the state.citation needed It includes questions about justice, law, property and the rights and obligations of the citizen. Politics and ethics are traditionally linked subjects, as both discuss the question of how people should live together.citation needed

Philosophy of religion

Philosophy of religion deals with questions that involve religion and religious ideas from a philosophically neutral perspective (as opposed to theology which begins from religious convictions). Traditionally, religious questions were not seen as a separate field from philosophy proper, the idea of a separate field only arose in the 19th century.v

Issues include the existence of God, the relationship between reason and faith, questions of religious epistemology, the relationship between religion and science, how to interpret religious experiences, questions about the possibility of an afterlife, the problem of religious language and the existence of souls and responses to religious pluralism and diversity.

Metaphilosophy

Metaphilosophy explores the aims of philosophy, its boundaries and its methods.