The cure of the part should not be attempted without the cure of the whole.
No one is a friend to his friend who does not love in return.
For our discussion is on no trifling matter, but on the right way to conduct our lives.
It is not noble to return evil for evil, at no time ought we to do an injury to our neighbors.
Those who have a natural talent for calculation are generally quick-witted at every other kind of knowledge; and even the dull, if they have had an arithmetical training, although they may derive no other advantage from it, always become much quicker than they would have been.
It was Plato, according to Sosigenes, who set this as a problem for those concerned with these things, through what suppositions of uniform and ordered movements the appearances concerning the movements of the wandering heavenly bodies could be preserved.