The conditional truth holds before the decree: prior in reason to absolute futurity
Next, if it is true that Peter, placed in certain circumstances, sins, then it was certainly true that if he were placed in them he would sin. This was true not only before he was placed in them, but even before God decreed that he should be placed in them. So God knew, before his decree, that this would happen under such a condition.
And in the order of reason, before it is true that something will absolutely happen, it is true that it would happen conditionally.
Latin
XVI. Deinde si verum est, quod Petrus positus in talibus circumstantiis peccet, sane non solum antequam in iis poneretur, sed etiam antequam in iis ex decreto Dei ponendus esset, verum erat, quod si in iis poneretur, peccaret, adeoque Deus ante suum decretum novit istud sub tali conditione futurum fuisse. Et prius ratione quam verum sit aliquid absolute futurum, verum est illud fuisse futurum conditionate.