Various specializations of philosophy and their subject matters include:

• Ethics: how human beings ought to behave in matters involving human well-being or harm.

• Philosophy of science: answers to questions of what science is, how science progresses, and the nature of scientific truth.

• Social and political philosophy: accounts of how society and government work as institutions, what their purposes should be, how they came into being as institutions and how their problems can be fixed.

• Epistemology: answers to questions about what knowledge is, how we know that something is true, and the relation between sense perception and abstract truths.

• Metaphysics: the most general questions and answers about the nature of reality, what physical things are, what relations exist between different kinds of things, and the connections between the mind and the world.

• Philosophy of mind: how the mind works, whether it is dependent on the brain, how it is connected to the body, the nature of memory and personal identity.

• Aesthetics: the study of art toward an understanding of what beauty is and how artworks are different from natural things and other man-made objects.

• Ancient philosophy: the birth of Western philosophy from about 800 B.C.E. to 400 C.E.; it is composed mostly of Greek and Roman thought before Christianity.

• Medieval philosophy: The development of philosophical thought, from about 400 C.E. until the Renaissance in the 1300s in Europe in which Christianity, provided the dominant world view and organizing principle for daily life.

• Modern philosophy: the foundations of contemporary philosophy from the 1600s through the 1800s.

• Nineteenth century philosophy: The “classical period” of modern philosophy, in which Friedrich Hegel, Immanuel Kant, and John Stuart Mill wrote.

• Analytic philosophy: style of professional philosophy, which is abstract and technical, that developed during the twentieth century.

• Post-modern philosophy: school of thought that, in the second half of the twentieth century, consisted of reactions against many of the shared assumptions held by philosophers over the centuries.