Aelianus is not allowed to join in this discussion 🙂 Unless I have made a definite mistake. Then he is not merely allowed but humbly (well, okay, pridefully) asked to point it/them out.

There are the twin issues of knowing the truth in the first place, and then having the appropriate attitude to it (and to other people in the light of it) .. but it’s not bare truth or knowledge that sanctifies: it needs to be mixed with faith in the hearts of those who hear it, if it’s going to do them any substantive good.

… my understanding would have been that the essential ingredient of saving faith is trust. (And that trust is indeed an ingredient or element of faith, not so much a consequence of it.)

Hmm. If I owned a copy of Joseph Pieper’s Faith as a philosophical problem I would post it to you, if you were to express an interest in or willingness to read it on my proposing it to you. It’s an essay, not a book. And is very good. However, at the moment there is no copy in my possession.

You can see I am sure that we are working with different terminologies. Mine – not that I worked it out for myself, or have even worked it out completely – is, I submit, closer to the reality of how humans work and of what Scripture says.

“it’s not bare truth or knowledge that sanctifies…

Well,  insofar as it is God who sanctifies, and God who is the first of all truths, then it is indeed bare truth that sanctifies, but obviously you were talking about something else. You are equally obviously right in saying that knowledge per se does not sanctify. Faith, as that earlier passage from the Summa  points out, is from God. Not a new observation. “By grace ye are saved through faith, and that not of yourselves: it is a gift of God”. Faith is necessary to salvation, as the quotation from the new Catechism of the Catholic Church in Aelianus’ last post states. But it is not sufficient. “Though Ihave all faith, so that I could remove mountains, and have not charity, I am nothing. And if I should distribute all my goods to feed the poor, and if I should deliver my body to be burned, and have not charity, it profiteth me nothing.” 

“To believe” is the verb that corresponds to “faith”. Faith is of the intellect, somewhere, as Thomas explains, between knowledge and opinion. Unlike opinion, it is certain. Unlike knowledge, it is not evident, though the very acute intellect (such as that of a demon) can be compelled to believe by signs. Pieper suggests the following analogy, though my presentation will be skewed by what I got out of it and a sloppy memory. It is wartime. My brother has been missing for several years. All that can be found out suggests that he is dead. Then someone comes to the house, claiming to have known my brother and claiming that he is alive and held prisoner far away. From details that he is able to provide it seems that he did indeed know my brother, other details of his story I am able to verify elsewhere, and in making a closer acquaintance over several days I become convinced of the man’s trustworthiness. I begin to look for my brother. Time, money, humilitations, difficulties, discouragements: through all these costs the thing that keeps me going is belief in what this man has told me, on the basis of what he has said and the kind of person he is. I don’t know  that my brother is alive. All I have to go on in this matter is the word of one man. I choose to believe. I think (and therefore act) assenting to the words of this man. 

I do not trust the man because of what he says about my brother. I believe what he says about my brother because I have seen, shown,  that he is trustworthy. Because I choose to believe him – after all, despite his demonstrated trustworthiness, and lack of a motive to lie, I could choose not to – I in a sense know something more than I would otherwise. As with most “knowledge”, for that matter. I don’t personally know that polar bear liver is poisonous because of the high concentration of vitamin A. I believe that it is on the basis of having read that this is so. I trust the writer, and believe what he tells me.

If you think about the words of Our Lord in the gospel of St John, he says something similar. “If you will not believe me, believe the works I do, so that you may know and understand that the Father is in me and I am in the Father”. He doesn’t show that He is God, so that you cannot not see it. He demonstrates that you should believe Him.

As you said elsewhere, the important question is “What *about* Jesus do you believe, and what’s its source?” (my underlining).  What do we believe, and on what grounds do we believe it?

If that chap had not turned up to my door, and I were to continue looking for my brother “believing” that he was still alive, since, for example, many other people were discovering long-lost relatives, there were many reports of otherwise unkown prisoner-of-war camps in remote areas that were taken over by local warlords in the general chaos, my brother was unusually fit and resourceful, and because I refused to admit that there was no chance of his being alive, then I would be working on opinion and hope, not faith. (faith in the writers of the reports, perhaps!). My opinion based on the evidence before me, and hope.

I have rather lost my train of thought, so will stop here. And in any case should be doing something else! But if you have the time and inclination, and would be so inclined, do explain how, in your understanding, “trust is an ingredient or element of faith, not so much a consequence of it”. 

The only thing I can think of is something along the lines of faith being used in a special sense applicable only to faith about good people and God, because the nature of the truth about them is that you should trust them (with allowances for the obvious measureless difference between a good person and God, and consequently your trust in them) – but I don’t see what “trust” brings that believing in the Christian faith and living according to it doesn’t.