To comprehend a man's life, it is necessary to know not merely what he does but also what he purposely leaves undone. There is a limit to the work that can be got out of a human body or a human brain, and he is a wise man who wastes no energy on pursuits for which he is not fitted; and he is till wiser who, from among the things that he can do well, chooses and resolutely follows the best.

To comprehend a man's life, it is necessary to know not merely what he does but also what he purposely leaves undone. There is a limit to the work that can be got out of a human body or a human brain, and he is a wise man who wastes no energy on pursuits for which he is not fitted; and he is till wiser who, from among the things that he can do well, chooses and resolutely follows the best.

To comprehend a man's life, it is necessary to know not merely what he does but also what he purposely leaves undone.