Bad men excuse their faults; good men abandon them

Nothing would be done at all if one waited until one could do it so well that no one could find fault with it.

It is almost the definition of a gentleman to say that he is one who never inflicts pain

A man would do nothing if he waited until he could do it so well that no one could find fault.

But, by all thy nature's weakness, Hidden faults and follies known, Be thou, in rebuking evil, Conscious of thine own.

Nobody can be perfect unless he admits his faults, but if he has faults how can he be perfect?