(1) Can one freely choose to act in a manner that one fully knows will lead to eternal hell? And even if one could, (2) Would a perfectly loving, just, and merciful God allow someone to make such a choice?
Let us assume, for the moment, that one could, with adequate knowledge, freely make such a choice if God allowed it. The question is, How could a perfectly loving, just, and merciful God allow it? As I understand it, the Church teaches that he does it because he gives us freedom and respects our capacity to exercise it. But this is how I look at it. If I were a human parent, I too would want my child to exercise as much freedom as possible. However, if I knew that he had a proclivity for pouring gasoline over himself and setting himself on fire, I would not allow him to do it if I could prevent it. Even if I thought he was choosing this with full knowledge of the consequences and completely free of any pathological compulsion to do it, which I almost certainly wouldn't (but we can get into that later), I wouldn't believe that his freedom should extend as far as his bringing such horrible pain and death to himself. And I don't think I'm being foolish in thinking that as bad as this kind of death would be, it is infinitesimally so compared to spending eternity completely isolated from all love and goodness. It just seems inconceivable to me that any parent--human or divine--could allow someone enough "freedom" to choose such an awesomely horrible fate for himself. It seems entirely unloving, unjust, and unmerciful.
But then it also seems to me that no one who fully knew God's love and the joys of heaven on the one hand, and the awfulness of isolation from God, love, and goodness for eternity that goes with rejecting God on the other could freely make such a choice. I know I'm repeating what I've posted before, and I admit that I can't prove it, but everything I think I know about human nature and psychology tells me that people naturally seek to experience pleasure and avoid pain and would, therefore, not knowingly choose to reject eternal joy in heaven for eternal pain in hell unless they were overwhelmed by an irresistible compulsion to do it. Yet, it also seems to me that unless someone has experienced God's love in a very powerful and direct way and/or the horrible isolation of hell in an equally powerful and direct way, he lacks the fullness of knowledge to make a sufficiently "informed" choice between them for which he can justly be held accountable.
And this is why I have said, time and again, that I find a hell of eternal suffering in total isolation from any vestige of God, goodness, and love to be utterly incompatible with a God of perfect love, justice, and mercy.
So far, my discussion partner hasn't replied. However, I suspect that he will in time, and that he will challenge me to refine my objections even further. Who knows? He may even persuade me to abandon my objections and embrace the Catholic position on hell and, ultimately, the Catholic faith. Now THAT would be a miracle!