M. Tullius Cicero, Laelius on friendship
William Armistead Falconer, Ed.

[63] Hence it is the part of wisdom to check the headlong rush of goodwill as we would that of a chariot, and thereby so manage friendship that we may in some degree put the dispositions of friends, as we do those of horses, to a preliminary test. Some men often give proof in a petty money transaction how unstable they are; while others, who could not have been influenced by a trivial sum, are discovered in one that is large. But if any shall be found who think it base to prefer money to friendship, where shall we find those who do not put office, civil and military rank, high place and power, above friendship, so that when the former advantages are placed before them on one side and the latter on the other they will not much prefer the former? For feeble is the struggle of human nature against power, and when men have attained it even by the disregard of friendship they imagine the sin will be forgotten because [p. 175] friendship was not disregarded without a weighty cause.