Laws of thought and principles of logic
Logic and Metalogic

The laws of thought are universal laws that apply (or not!) to thought in general and reasoning in particular, enabling us to justify inferences and, more generally, reasoning and argumentation.

Philosophy is a discipline of the human sciences that deals with knowledge, understanding the world and life through rational and critical reflection, guided by the search for truth. Philosophy has spawned fundamental fields of study such as logic. Unlike mathematics, philosophy has never decided to use formal symbols alone, although G. Leibniz did aspire to treat philosophical problems by means of a formal language and a universal logical calculus.

Metaphysics is the branch of philosophy that addresses the fundamental questions of first principles of being, nothingness, identity and change, causality and possibility.

Psychology...