PhilosophyPhilosophy (love of wisdom in ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, values, mind, and language. It is a rational and critical inquiry that reflects on its own methods and assumptions. Historically, many of the individual sciences, like physics and psychology, formed part of philosophy. But they are considered separate academic disciplines in the modern sense of the term.
Mind–body problemThe mind–body problem is a philosophical problem concerning the relationship between thought and consciousness in the human mind, and the body. The issue is this. Though it is obvious that mental events and physical events are somehow related, it is not obvious what the nature of this relation is. For example, it is obvious that feelings of sadness (which are mental events) will cause people to cry (which is a physical state of the body), or that finding a joke funny (a mental event) will cause one to laugh (another bodily state), or that feelings of pain (in the mind) will cause avoidance behaviours (in the body), and so on.
Best of all possible worldsThe phrase "the best of all possible worlds" (Le meilleur des mondes possibles; Die beste aller möglichen Welten) was coined by the German polymath and Enlightenment philosopher Gottfried Leibniz in his 1710 work Essais de Théodicée sur la bonté de Dieu, la liberté de l'homme et l'origine du mal (Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil), more commonly known simply as the Theodicy. The claim that the actual world is the best of all possible worlds is the central argument in Leibniz's theodicy, or his attempt to solve the problem of evil.
A priori and a posterioriA priori ("from the earlier") and a posteriori ("from the later") are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on experience. A priori knowledge is independent from any experience. Examples include mathematics, tautologies, and deduction from pure reason. A posteriori knowledge depends on empirical evidence. Examples include most fields of science and aspects of personal knowledge. The terms originate from the analytic methods found in Organon, a collection of works by Aristotle.