(uncountable, originally) The love of wisdom.

(uncountable) An academic discipline that seeks truth through reasoning rather than empiricism, often attempting to provide explanations relating to general concepts such as existence and rationality.

(countable) A comprehensive system of belief.

(countable) A view or outlook regarding fundamental principles underlying some domain.

(countable) A general principle (usually moral).

A calm and thoughtful demeanor; calmness of temper.

(now rare) To philosophize.