He therefore occupies himself with improving the character of wild trees, and making them fruitful, and with further improving the character of fruitful trees by his care, and with reducing by pruning those branches which through superfluity of nourishment are too luxuriant, and with inducing those which are contracted and crowded to grow by the extension of their young shoots. Moreover, those trees which are of good sorts, and which make many shoots, he propagates by extending them under the earth in ditches of no very great depth, and those which do not produce good fruit he endeavours to improve by the insertion of other kinds into their roots, connecting them by the most natural union.
For the same thing happens likewise in the case of men, that they firmly unite into their own family adopted sons, who are unconnected with them in blood, but whom they make their own on account of their virtues. The husbandman, therefore, takes up innumerable shoots, with their roots entire, which have by natural process become barren, as far as bearing fruit is concerned, and which even do great injury to those plants which
 
do bear by reason of their being planted near them. Such, then, is the art which is applied to those plants which grow out of the ground. And now let us turn our consideration to the husbandry of the soul in its turn.
 First of all, therefore, the husbandman is not anxious to plant or to sow anything that is unproductive, but only all such things as are worth cultivation, and as bear fruit, which will bring a yearly produce to their master man. For nature has pointed him out as the master of all trees and animals, and all other things whatever which are perishable; and what can man be but the kind that is in every one of us, which is accustomed to reap the advantage from all that is sown or planted? But since milk is the food of infants, but cakes made of wheat are the food of fullgrown men, so also the soul must have a milk-like nourishment in its age of childhood, namely, the elementary instruction of encyclical science. But the perfect food which is fit for men consists of explanations dictated by prudence, and temperance, and every virtue.
For these things being sown and implanted in the mind will bring forth most advantageous fruit, namely, good and praiseworthy actions. By means of this husbandry, all the trees of the passions and vices, which shoot forth and grow up to a height, bringing forth pernicious fruits, are rooted up, and cut down, and cleared away, so that not even the smallest fragment of them is left, from which any new shoots of evil actions can subsequently spring up.