De Agricultura

Therefore, as we found a tiller of the earth and a husbandman, though there did not appear to be any difference between them (till we came to investigate the allegorical meaning concealed under each name), nevertheless very far removed from one another in fact, such also shall we find to be the case with a shepherd and a keeper of sheep. For the lawgiver sometimes speaks of the occupation of a shepherd, and sometimes of that of a keeper of sheep.