XXXI. (170) There is also a third definition of what is taught a man by himself, namely that which of its own accord rises upwards. For it is said in the hortatory injunctions, "Ye shall not sow, neither shall ye reap those things which arise from the earth of their own Accord."[Ge 25:11.] For nature has not need of any art since God himself sows those things, and by his agricultural skill brings to perfection, as if they grew of themselves, things which do not grow of themselves, except inasmuch as they stand in need of no human assistance whatever. (171) But this is not so much a positive exhortation as an announcement of his opinion, for if he had been giving a positive recommendation he would have said, "Do not sow, and do not reap:" but as he is only giving his opinion, he says, "Ye shall not sow, neither shall ye reap." For as to those things with which we meet by the voluntary bounty of nature, of these we cannot find either the beginnings or the ends in ourselves as if we were the cause of them: therefore the beginning is the seed-time and the end the harvest time. (172) And it is better to understand these things thus: every beginning and every end is spontaneous, that is to say, it is the work of nature and not of ourselves. For instance; what is the beginning of learning. It is plain that it is a nature in the person who is taught which is well calculated to reeive the particular subjects of meditation submitted to him. Again what is the beginning of being made perfect? If we are to speak plainly without keeping anything back, it is nature. Therefore he who teaches is also indeed to effect improvement, but it is God alone, the most excellent nature of all, who is able to conduct one to supreme perfection. (173) He who is bred up among such doctrines as these has everlasting peace, and is released from wearisome and endless labours. And according to the lawgiver there is no difference between peace and a week; for in each creation lays aside the appearance of energising and rests. (174) Very properly, therefore, is it said, "And the sabbath of the law shall be food for you," speaking figuratively. For the only thing which is really nourishing and really enjoyable is rest in God; which confers the greatest good, undisturbed peace. Peace, therefore, among cities is mixed up with civil war; but the peace of the soul has no mixture in it of any kind of difference. (175) And the lawgiver appears to me to be recommending most manifestly that kind of discovery which is not preceded by any search, in the following words, "When the Lord thy God shall lead thee into the land which he swore to thy fathers that he would give thee, large and beautiful cities which thou buildest not, houses full of all good things which thou filledst not, cisterns hewn out of the quarries which thou hewedst not, vineyards and olive gardens which thou plantedst Not."[De 6:10.] (176) You see here the ungrudging abundance of all the great blessings which are ready, and poured forth for man's possession and enjoyment. And the generic virtues are here likened to cities, because they are of the most comprehensive kind; and the specific virtues are likened to houses, because they are contracted into a narrower circle; and the souls of a good disposition are likened to cisterns, which are well inclined to receive wisdom, as the cisterns are calculated to receive water; and the improvement, and growth, and production of fruit, are compared to vineyards and olive gardens; and the fruit of knowledge is a life of contemplation, which produces unmixed joy, equal to that which proceeds from wine; and a light appreciable only by the intellect, as if from a flame of which oil is the nourishment.