It is well: the foundations are laid, as the illustrious orator says. But we have not only laid the foundations, which might be firm and suitable for the support of the work; but we have raised the entire edifice, with great and strong buildings, almost to the summit. There remains, a matter which is much easier, either to cover or adorn it; without which, however, the former works are both useless and displeasing. For of what avail is it, either to be freed from false religions or to understand the true one? Of what avail, either to see the vanity of false wisdom, or to know what is true? Of what avail is it, I say, to defend that heavenly justice? Of what avail to hold the worship of God with great difficulties, which is the greatest virtue, unless the divine reward of everlasting blessedness attends it? Of which subject we must speak in this book, lest all that is gone before should appear vain and unprofitable: if we should leave this, on account of which they were undertaken, in uncertainty, lest any one should by chance think that such great labours are undertaken in vain; while he distrusts their heavenly reward, which God has appointed for him who shall have despised the present sweet enjoyments of earth in comparison of solitary and unrewarded virtue. Let us satisfy this part of our subject also, both by the testimonies of the sacred writings and also by probable arguments, that it may be equally manifest that future things are to be preferred to those which are present; heavenly things to earthly; and eternal things to those which are temporal: since the rewards of vices are temporal, those of virtues are eternal.