The reasons for determinate truth in absolute future propositions hold for these conditionals too
The reasons that lead us to hold that absolute propositions about contingent futures are determinately true or false seem to apply to these conditionals as well. One is that of two contradictories one must be true and the other false. Another is that in every true disjunction at least one part must be true.
For this disjunction is true: if Peter is placed in such an occasion and God does not deny him his usual concurrence, he will sin or he will not sin. These two propositions also contradict each other: 'If Peter is placed in that order of things and God is not unwilling to concur with him in acting, he will do this,' and 'If Peter is placed in that order of things and God is not unwilling to concur with him in acting, he will not do this.'
Latin
XLVII. Et certe quae rationes suadent absolutas propositiones de futuris contingentibus determinatam veritatem, vel falsitatem habere, in hisce conditionatis locum etiam habere videntur. Nempe quod fieri non potest, quin ex duabus contradictoriis, altera sit vera, altera falsa. Item quod in omni disjunctiva vera, una pars saltem debet esse vera. Nam haec disjunctiva vera est, Si Petrus in occasione tali constituatur, nec Deus ei solitum concursum suum deneget, peccabit, vel non peccabit. Et hae quoque duae sibi mutuo contradicunt, Petrus si in eo rerum ordine collocetur, nec Deus nolit cum eo ad agendum concurrere, hoc aget. Et Petrus si in eo rerum ordine collocetur, nec Deus nolit cum eo ad agendum concurrere, hoc non aget.