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.
Studies are the food of youth, the delight of old age; the ornament of prosperity, the refuge and comfort of adversity; a delight at home, and no hindrance abroad; they are companions by night, and in travel, and in the country.
The happiest end of life is this: when the mind and the other senses being unimpaired, the same nature which put it together takes asunder her own work.
Now in regard to trades and other means of livelihood, which ones are to be considered becoming to a gentleman and which ones are vulgar, we have been taught, in general, as follows. First, those means of livelihood are rejected as undesirable which incur people's ill-will, as those of tax-gatherers and usurers. Unbecoming to a gentleman, too, and vulgar are the means of livelihood of all hired workmen whom we pay for mere manual labour, not for artistic skill; for in their case the very wage they receive is a pledge of their slavery.