"The understanding can understand many things together, taking them as one, but not many things together, taking them as many. By 'taking them as one or many' I mean, by one or by several intellectual presentations. . . . . Whatsoever things therefore the mind can understand by one presentation, it can understand together. Hence God sees all things by one thing, which is His essence." -- St Thomas, Sum.Theol. I, q. 85, art. 4.
Of God and His Creatures: 1.69