Labour to know thine own frame and temper; what spirit thou art of; what associates in thy heart Satan hath; where corruption is strong, where grace is weak; what stronghold lust hath in thy natural constitution, and the like. . .
Be acquainted, then, with thine own heart: though it be deep, search it; though it be dark, inquire into it; though it give all its distempers other names than what are their due, believe it not.
-John Owen, Of Temptation
