philosophy

The study of the nature, causes, or principles of reality, knowledge, or values, based on logical reasoning.

A system of thought based on or involving such study.

The study of the theoretical underpinnings of a particular field or discipline.

An underlying theory or set of ideas relating to a particular field of activity or to life as a whole.

The body of highest truth; the organized sum of science; the science of which all others are branches; the science of the most fundamental matters..