The philosophy of the mind deals with the examination of problems revolving around the concept of the mind. The mental may be distinguished from the physical in various ways: intentionality and consciousness provide important features of mental states.

An important part of the argument is the claim that mental states are known in a special way: they are directly given, transparent to their owner and known infallibly. Monist and materialist believe that reality is physical and explained by natural science; sought in various ways to understand the mind in material terms.

Behaviourism advocates that psychology should concern itself exclusively with observation of behaviour, disregarding introspection altogether.

Others propose that mental states are the same as states of the brain. Dissatisfaction with these overly simple attempts to incorporate the mental into the physical realm led to the development of functionalism.