Estius's answer: freedom requires choice from a judgment that could have been otherwise; only uncreated will has its choice from no prior
His answer is that for the nature of free choice it is enough that the will, on a prior judgment of the practical intellect, chooses one of two opposites in such a way that it could choose the other on a different judgment of the same intellect. The root and foundation of freedom of choice lies in the intellect, insofar as it can weigh different aspects of good in opposite options and set them before the will.
The nature of free choice does not require that a free agent, when it chooses on a prior judgment, should not be moved by some higher cause to judge and choose as it does. So, since God's motion predetermining the will does not prevent a man from having a full and complete judgment of reason, judging one means contingent and another necessarily connected with the end, and being able to choose differently on a different judgment, that motion does the freedom of our will no harm. It belongs only to the uncreated will not to receive its choice from something prior.
Latin
XXIII. Ad hoc vero respondet ad rationem liberi arbitrii; hoc sufficere, ut ex praevio judicio intellectus practici, sic eligat unum oppositorum, ut tamen ex ejusdem intellectus diverso judicio possit eligere alterum; quia, scilicet, radix & fundamentum libertatis arbitrii est in intellectu, quatenus ille diversas boni rationes circa opposita potest considerare, & voluntati proponere, rationem vero liberi arbitrii non includere, ut dum agens liberum ex judicio praevio eligit, ad sic judicandum atque eligendum non moveatur ab aliqua causa superiori. Ac proinde cum motio Dei voluntatem praedeterminans non impediat quominus homo plenum atque perfectum habeat judicium rationis, & judicet aliud medium esse contingens, aliud autem cum fine ex necessitate connexum, & posset quoque ex diverso judicio aliud eligere, hoc ipso, talem motionem libertati Voluntatis nostrae nihil officere. Quippe proprium esse Voluntatis increatae ut electionem suam ab aliquo priori non habeat.