Principle is on the Academic Vocabulary List.

(countable) Principles are personal rules that tell you what is right and wrong.
It goes against my principles to ignore her.

One principle I follow is not to have regret.
(countable) A principle is the general idea that explains or supports something.
The basic principle of his chair is that the knees should be below the hips.

Police must not accept money because it could affect their judgement. The same principle applies if gifts, etc, are offered.

Noun