"Wretched and barren is the discontent, that quarrels with its tools instead of with its skill."
The tools represent our circumstances: the skill represents our character.
We make excuses for our behavior and blame our circumstances -- We say
'How gentle we would be, if we were not provoked; how devoted we would be, if we were not so busy; we would be patient, if we were not sick; we would do great things, but we will have to wait for a time of golden leisure, when confusion is to cease;
Life, to be set in order, is just unattainable in this season.' We act as if time and change should be our servants, and made to do the bidding of our conscience.
Once let a man insult the majesty of duty, by waiting till its commands shall become easy, and he will be disowned as an outlaw from her realm." Martineau.