Man's main task in life is to give birth to himself, to become what he potentially is. The most important product of his effort is his own personality. One can judge objectively to what extent a person has succeeded in his task, to what degree he has realized his potentialities. If he has failed in his task, one can recognize this failure and judge it for what it is - a moral failure.
'Man for Himself' (1947) ch. 4