Strang's argument: conditionals without necessary connection cannot be known with certainty, so not by God
Strang does not agree with the theologians just named that the futurity of every event from eternity depends on nothing but God's free decree. He tries to prove by another argument, which he considers unanswerable, that God cannot know free contingents as future on any supposition from which the determination of the created will does not necessarily follow.
His argument runs like this. Conditionals whose consequent has no necessary connection with the antecedent cannot be known with certainty, and so God cannot know them either, since his knowledge is entirely certain and infallible. The conditionals said to be the object of middle knowledge are of this kind, and so on.
He proves the major premise as follows: 'Unless the object is certainly true, it cannot be known with certainty. As long as the matter is uncertain, it cannot be known with certainty. But nothing is certainly true that is not necessarily true, necessarily, I mean, either absolutely or on a hypothesis.
So for conditional knowledge to be certain and infallible, its object must be a necessary conditional proposition. And no conditional proposition is necessary unless the inference in it is necessary.' Treatise on the Will of God concerning Sin, book 3, chapter 11.
Latin
XLIV. Strangius vero qui non putat, cum modo dictis Theologis, cujuslibet eventus ab aeterno futuritionem non aliunde quam ex Dei libero decreto pendere, alio argumento, quod invictum esse existimat, probare contendit contingentia libera, ut futura non posse a Deo cognosci, ex ulla hypothesi, ex qua non necessario inferatur determinatio voluntatis creatae. Argumentum autem ejus tale est. Conditionata quorum consequens non habet necessariam connexionem cum antecedente non possunt certo sciri, ac proinde nec sunt scibilia a Deo, cujus scientia est certissima & omnino infallibilis. At ejusmodi sunt conditionata quae statuuntur esse objectum scientiae mediae, &c. Majorem probat, quia, inquit, Nisi objectum sit certo verum, certo cognosci non potest: quamdiu enim res est incerta, certo sciri non potest; nihil autem est certo verum quod non est necessario verum, necessario inquam vel absolute, vel ex hypothesi. Ac proinde conditionata scientia ut sit certa & infallibilis, oportet ut objectum ejus sit conditionata propositio necessaria: nulla autem conditionalis propositio est necessaria, in qua illatio non est necessaria. Tractatu de Voluntate Dei circa peccatum lib. 3. cap. 11.