The most evident difference between man and animals is this: the beast, in as much as it is largely motivated by the senses and with little perception of the past or future, lives only for the present. But man, because he is endowed with reason by which he is able to perceive relationships, sees the causes of things, understands the reciprocal nature of cause and effect, makes analogies, easily surveys the whole course of his life, and makes the necessary preparations for its conduct.
Marcus Tullius CiceroWe cannot employ the mind to advantage when we are filled with excessive food and drink.
Marcus Tullius CiceroThe man who commands efficiently must have obeyed others in the past, and the man who obeys dutifully is worthy of someday being a commander.
Marcus Tullius Cicero