In a general sense, the cause, source or origin of any thing; that from which a thing proceeds; as the principle of motion; the principles of action.

Element; constituent part; primordial substance. Modern philosophers suppose matter to be one simple principle, or solid extension diversified by its various shapes.

Being that produces any thing; operative cause. The soul of man is an active principle.

In science, a truth admitted either without proof, or considered as having been before proved. In the former sense, it is synonymous with axiom; in the latter, with the phrase, established principle.

Ground; foundation; that which supports an assertion, an action, or a series of actions or of reasoning. On what principle can this be affirmed or denied? He justifies his proceedings on the principle of expedience or necessity. He reasons on sound principles.

A general truth; a law comprehending many subordinate truths; as the principles of morality, of law, of government.

Tenet; that which is believed, whether truth or not, but which serves as a rule of action or the basis of a system; as the principles of the Stoics, or of the Epicureans.

A principle of human nature, is a law of action in human beings; a constitutional propensity common to the human species. Thus it is a principle of human nature to resent injuries and repel insults.

To establish or fix in tenets; to impress with any tenet, good or ill; chiefly used in the participle. Men have been principled with an opinion, that they must not consult reason in things of religion.

To establish firmly in the mind.