Self-Knowledge
Charles Buck Theological Dictionary [1]
The knowledge of one's own character, abilities, duties, principles, prejudices, tempers, secret springs of action, thoughts, memory, taste, views in life, virtues, and vices. This knowledge is commanded in the Scriptures, Psalms 4:4 . 2 Corinthians 13:5 . and is of the greatest utility, as it is the spring of self-possession, leads to humility, steadfastness, charity, moderation, self-denial, and promotes our usefulness in the world. To obtain it, there should be watchfulness, frequent and close attention to the operations of our own minds, regard had to the opinions of others, conversation, reading the Scriptures, and dependence on divine grace.
See Mason on Self-knowledge; Baxter's Self-Acquaintance; Locke on the Underst.; Watts's Improvement of the Mind.
Webster's Dictionary [2]
(n.) Knowledge of one's self, or of one's own character, powers, limitations, etc.