A belief held by Calvinism that man is totally unable to save himself.  Man is sinful through and through and the only way that he can be saved is by an act of God.  Man must be elected by God in order to be saved because his depraved nature does not allow him to choose God.

Some argue that the word total is unnecessary as depravity by definition implies totality.

Arminians also believe that man will not seek God on his own as is taught by scripture.  To address this fact, they believe that God must extend prevenient grace which allows humanity to choose God.

See also: unconditional election, limited atonement, irresistible grace