Given what has already been said, the question naturally arises: what do we make, then, of the fact that God seems to change course at various points in revealed history?1
Opus, non consilium apud Deum mutari, nec variari eum quia per varia tempora diversa praecepit; sed manens idem incommutabilis et aeternus, quid cuique congruum esset tempori ab ipsa aeternitate in eius mansit disputatione consilii.[We believe] that for God his work undergoes change, not his plan, and that he is not caused to vary because he has commanded different things over the course of various times; but [he has done so while] remaining the same, immutable and eternal. What is right for each one at any given time has remained from eternity itself in the reasoning of his plan.
What God does externally–his opus–may undergo variation, but in a way that was always contained internally in his plan–his consilium. God is unchangeable,2 and so the counsel of his will is unchangeable. What changes is the manifestation of that will in his various works in the world.
For our part, we dare not believe that God is affected in one way when He works, in another when He rests. Indeed, to say that He is affected at all, is an abuse of language, since it implies that there comes to be something in His nature which was not there before. For he who is affected is acted upon, and whatever is acted upon is changeable. His leisure, therefore, is no laziness, indolence, inactivity; as in His work is no labor, effort, industry. He can act while He reposes, and repose while He acts. He can begin a new work with (not a new, but) an eternal design; and what He has not made before, He does not now begin to make because He repents of His former repose. But when one speaks of His former repose and subsequent operation (and I know not how men can understand these things), thisformerandsubsequentare applied only to the things created, which formerly did not exist, and subsequently came into existence. But in God the former purpose is not altered and obliterated by the subsequent and different purpose, but by one and the same eternal and unchangeable will He effected regarding the things He created, both that formerly, so long as they were not, they should not be, and that subsequently, when they began to be, they should come into existence. And thus, perhaps, He would show, in a very striking way, to those who have eyes for such things, how independent He is of what He makes, and how it is of His own gratuitous goodness He creates, since from eternity He dwelt without creatures in no less perfect a blessedness.