principle

A basic truth, law, or assumption.

A rule or standard, especially of good behavior.

The collectivity of moral or ethical standards or judgments.

A fixed or predetermined policy or mode of action.

A basic or essential quality or element determining intrinsic nature or characteristic behavior.

A rule or law concerning the functioning of natural phenomena or mechanical processes.

One of the elements that compose a substance, especially one that gives some special quality or effect.

A basic source.

(in principle) With regard to the basics.