The effect produced by this great work it is impossible to determine with accuracy. Beugnot, with an absoluteness which we should condemn as presumption in any less competent authority, declares that its effect can only have been very slight. Probably its effect would be silent and slow; telling first upon cultivated minds, and only indirectly upon the people. Certainly its effect must have been weakened by the interrupted manner of its publication. It is an easier task to estimate its intrinsic value. But on this also patristic and literary authorities widely differ. Dupin admits that it is very pleasant reading, owing to the surprising variety of matters which are introduced to illustrate and forward the argument, but censures the author for discussing very useless questions, and for adducing reasons which could satisfy no one who was not already convinced. Huet also speaks of the book as "un amas confus d'excellents materiaux; c'est de l'or en barre et en lingots." L'Abbé Flottes censures these opinions as unjust, and cites with approbation the unqualified eulogy of Pressensé. But probably the popularity of the book is its best justification. This popularity may be measured by the circumstance that, between the year 1467 and the end of the fifteenth century, no fewer than twenty editions were called for, that is to say, a fresh edition every eighteen months. And in the interesting series of letters that passed between Ludovicus Vives and Erasmus, who had engaged him to write a commentary on the City of God for his edition of Augustine's works, we find Vives pleading for a separate edition of this work, on the plea that, of all the writings of Augustine, it was almost the only one read by patristic students, and might therefore naturally be expected to have a much wider circulation.