The Thomists' first foundation: all futures present to God in eternity, as to one on a watchtower (Alvarez)
The scholastic teachers work hard to get out of this difficulty and try in various ways to explain how God foreknows future contingent and free things.
The first are the later Thomists just mentioned. They lay two foundations for the certainty by which God foreknows every future contingent from eternity. The first is that all future things are present to God in eternity, not merely in objective or known being, but in real being, in their own actual existences.
'God,' they say, 'stands toward future contingents like someone on a high watchtower who surveys the whole road and everyone travelling along it. One traveller follows another and the one behind cannot see the one ahead, yet the watcher on the tower sees them all at once and has them present to himself. So likewise God has present to himself, on the watchtower of eternity, all things past and future, though the one succeeds the other.' These are the words of Didacus Alvarez, book 1, chapter 8.
There he further proves this presence of future things in eternity from the fact that eternity is an indivisible duration that exists whole all at once. Whatever coexists with eternity at any time therefore coexists with all of it, and so is present to all of it.
Latin
XXX. Ut ex difficultate ista se expediant, multum laborant Scholastici Doctores, & variis modis nituntur exponere, qua ratione Deus futura contingentia & libera praesciat. Et primo quidem illi, qui modo jam dicti sunt, Thomistae recentiores, certitudini isti qua Deus ab aeterno futura quaelibet contingentia praescit, duo fundamenta praestruunt. Unum est res omnes futuras in aeternitate Deo praesentes esse, non tantum in esse objectivo, sive in esse cognito: sed etiam in esse reali, & secundum proprias suas existentias. Nam, inquiunt, ita se habet Deus in ordine ad futura contingentia, sicut existens in alta specula, ex qua intuetur totam viam in ordine ad transeuntes per illam; licet enim unus pergat post alium, & posterior non videat priorem; ille tamen qui est in specula, omnes simul intuetur, & habet praesentes sibi: ergo similiter Deus habet sibi praesentes in specula aeternitatis omnes res praeteritas, & futuras: licet istae succedant illis. Quae sunt verba Didaci Alvarez lib. 1. c. 8. Ubi praesentiam istam futurorum in aeternitate, inde praeterea probat, quod aeternitas est duratio indivisibilis tota simul existens: ideoque quicquid ullo tempore coexistit aeternitati, illi toti coexistit, & consequenter illi toti praesens est.