There are five main branches in philosophy, metaphysics, epistemology, ethics, politics, and aesthetics. Each branch contains a specific focus and area of study. When one remembers that philosophy is a form of science, this method of organization suddenly becomes crystal clear.
Metaphysics, as the name suggests, is the study of reality. Literally, the term metaphysics means ‘beyond the physical.’ Typically, this is the branch that most people think of when they picture philosophy. In metaphysics, the goal is to answer the what and how questions in life. In other words, metaphysics forms a foundation for which we can understand everything else.
Epistemology is the study and understanding of knowledge. Here, philosophers address questions such as the limitations of logic, how comprehension works, and the ability (or perception) to be certain. In short, the question of epistemology is ‘how do we know?’
As one might imagine, ethics is the study of morality, right and wrong, good and evil. Ethics tackles difficult conversations, adding weight to actions and decisions. This is the branch that birthed the famous Trolley Dilemma.
Politics takes ethics to a larger scale, applying it to a group (or groups) of people. Political philosophers study political governments, laws, justice, authority, rights, liberty, ethics, and much more.
Aesthetics is the study of art – and beauty. Here, philosophers try to understand, qualify, and quantify what makes art what it is. Aesthetics also takes a deeper look at the artwork itself, trying to understand the meaning behind it, both art as a whole and art on an individual level. A question an aesthetics philosopher would seek to understand is whether or not beauty truly is in the eye of the beholder.
Along with the five branches discussed above, there are two other categories worth considering, axiology and logic philosophy. Not all philosophers believe these subjects to be their own branch.
Axiology is the study of value and valuation. In contrast, logic is the study of reasoning. Much like metaphysics, understanding logic helps philosophers (and everyone else) understand and appreciate how we perceive the rest of our world. More than that, it provides a foundation for which to build and interpret arguments and analysis.