Becanus: God knows futures certainly by the infinite reach of his intellect and their determinate truth
Others say simply that God foreknows future contingents with certainty for this reason: whatever exists at some time, whether contingently or necessarily, was true as a future thing before it existed. Whatever is true the divine intellect knows with certainty, because no truth can be hidden from an infinite intellect, and the divine intellect is infinite.
So, on their view, 'the certainty of God's foreknowledge is to be sought from two sources. First, from the infinite power and penetration of the divine intellect. Second, from the determinate truth of future contingents.' These are the words of the Jesuit Becanus in his Summa of Theology, volume 1, treatise 1, chapter 10, question 11, first conclusion.
Latin
XXXVI. Alii vero simpliciter dicunt Deum certo praenosse futura contingentia, quia quicquid aliquando est, sive contingenter, sive necessario, antequam esset, verum fuit esse futurum: quicquid autem verum est certo cognoscit intellectus divinus; quoniam nulla veritas latere potest intellectum infinitum, qualis divinus est. Itaque juxta ipsos, Certitudo divinae praescientiae ex duplici capite petenda est. Primo ex infinita vi & perspicacitate divini intellectus. Secundo ex determinata veritate futurorum contingentium. Quae sunt verba Becani Jesuitae, in summa Theologiae tomo 1. tractatu 1. cap. 10. quaest. 11. conclusione prima.