Quotes by Subject:

Sufficient

He who is unable to live in society, or who has no need because he is sufficient for himself, must be either a beast or a god. – Aristotle.

No man undertakes a trade he has not learned, even the meanest; yet everyone thinks himself sufficiently qualified for the hardest of all trades, that of government. – Socrates.

The wise man does not expose himself needlessly to danger, since there are few things for which he cares sufficiently; but he is willing, in great crises, to give even his life - knowing that under certain conditions it is not worthwhile to live. – Aristotle.