Of course, "negative reprobation" cannot be reconciled with the Catholic doctrine of God's universal salvific will, so ultimately it must be rejected as untenable with said doctrine.
And yet it hasn't been rejected because you can't have election without reprobation.
It is a dogma of the faith that "God, by an eternal resolve of His will, predestines certain men, on account of their foreseen sins, to eternal rejection."
Then if God is condemning men for their foreseen sins, ergo, He isn't predestining them before considering their sins, which is what "negative reprobation" holds. Therefore, God does not condemn any man to Hell except in view of their deliberate rejection of His graces, and not as the Thomists hold, because He withholds the necessary graces that would enable them to be saved.
As I understand this (at least roughly thomistically, I think), God doesn't "first predestine some men to hell and enforce that by withholding necessary graces that would enable them to be saved". He, FOREKNOWING their sin (resisting sufficient grace, which they would do even if they knew of further grace) withholds the further grace (which they would REJECT if they could). He does not force grace on those who would reject it, but chooses from eternity to permit some to sin (and be damned). He
at the same time (not afterwards) chooses from eternity that other men freely do good (ensuring they are saved) and is the cause of that good. I think the mystery of both reprobation and predestination can't be understood without understanding what "God is outside of time" really means, in God's eyes. God is Sovereign over both good and evil in the whole Eternal tapestry of Divine Providence: the story of Creation, the Fall, the Redemption, and Salvation. He doesn't just stand by and watch how we all work it out ... even though we ARE freely working it out too.
It's not being forced to do evil if it is inevitable because God foreknows it from eternity. Nor is it being forced to do evil if it is inevitable because God permits it from eternity - even if He could have done otherwise. Saying "You could have NOT PERMITTED our sin if you REALLY loved us" to God is a childish refusal to take blame (and envy of others).
You can LOOK at simple foreknowledge as being a proof of fate; but in a lifetime people live freely and produce their own results.
You can LOOK at predestination (something God performs outside of time) as being a proof of a lack of freedom; but in a lifetime, a man
in a sense freely "lives himself into" being a reprobate, or into being saved (predestined):
...with fear and trembling work out your salvation.
As St. Paul goes on to say, it is God who works in you; but YOU are still working.
"Well I may as well live as I like since I can do nothing about it" is not true, nor is "I know I am saved since I accepted...". I think that in trusting in God you can put all this aside and live in hope and do good. That's what saints did, no matter what they thought about how predestination worked.
Yes it is hard to understand how the obvious truth of free-will is not violated by the idea of God's absolute sovereignty and causality of all good. But I accept both of these truths (as the Church teaches) and chalk up the problem to the weakness of my own intellect and that of all the myriads of theologians who have tried to explain them (even St. Thomas). How can our intellect compare to that of God? I don't think it is denying human reason to admit to the Mystery of Divine Providence.
I know I haven't "figured this out".