In the grand scheme of things, the debate over flat earth is non-essential and I wouldn't harbor any ill feelings towards anyone who rejects it; it just doesn't matter that much in life.

Well, truth always matters.  It matters enough to the liars in charge to have kept it hidden.  One thing that's certain with FE that you can't get from plain geocentrism is that with FE, "Intelligent Design" becomes absolutely unavoidable.  There are many FEs out there who were atheists at first but then converted to some kind of belief in God (at least at first step), but big-universe globe earth geocentrism could still be explained away.  Now, it just so happens that most geocentrists are "Christians" of some variety, but nearly all of them were Christian first.  I don't see atheists being convinced by the geocentric arguments of a Dr. Sungenis, whereas many people who aren't really believers have become convinced by FE merely due to the preponderance of evidence that anyone could go out there with a camera or telescope and obtain for themselves.  I think that the FE case is just much more "accessible" to average people than a lot of Sungenis' arguments for geocentrism, which are more obscure and require a much stronger ability to grasp scientific principles.

One thing that's certain with FE that you can't get from plain geocentrism is that with FE, "Intelligent Design" becomes absolutely unavoidable.  There are many FEs out there who were atheists at first but then converted to some kind of belief in God (at least at first step), but big-universe globe earth geocentrism could still be explained away.  Now, it just so happens that most geocentrists are "Christians" of some variety, but nearly all of them were Christian first.  I don't see atheists being convinced by the geocentric arguments of a Dr. Sungenis, whereas many people who aren't really believers have become convinced by FE merely due to the preponderance of evidence that anyone could go out there with a camera or telescope and obtain for themselves. 

Great points.  Never thought of it that way.  And didn’t know atheists converted due to FE.  God uses a million different ways but had not heard this way. 

I don't know if it's true, but Fr Hesse said St Thomas Aquinas was wrong about the Immaculate Conception, I think it was. So he could be wrong about what lions ate before the fall, but I am curious to hear his explanation.

However, without critical examination of the individual arguments, I think we must be careful when assuming that a mistake in one area means by default an error in others ...

Strawman.  Absolutely no one has ever held that "a mistake in one area means by default an error in others".  It's usually used an illustration for the pseudo-pious argument that Doctors of the Church are effectively infallible simply because the Church has approved them as Doctors.  And, yes, I have heard that posted on this forum, that since the Church's authority delared them Doctors, we must accept everything they taught as true.  It's usually been in the area of Baptism of Desire, and often by people who (ironically or hypocritically) reject St. Thomas' teaching that explicit faith in the Holy Trinity and Incarnation are required for salvation.

"Strawman: A form of argument and an informal fallacy based on giving the impression of refuting an opponent's argument, while actually refuting an argument that was not presented by that opponent"

With all due respect Ladislaus, I disagree. I'm not sure you understood the post.

You're "refuting" a position that absolutely no one holds, namely, that "a mistake in one area means by default an error in others".  Nobody has ever held that position here.

You're "refuting" a position that absolutely no one holds, namely, that "a mistake in one area means by default an error in others".  Nobody has ever held that position here.

Again with respect Ladislaus, as the previous posts reproduced below show, I never did infer guilt or accuse anyone here on the forum of the position you are referring to above. Unlike the strawman fallacy, which infers that the opponent believes something which they really do not (and which is subsequently refuted), I wasn't attempting to refute (or give the illusion of refuting) anyone here on this forum.  Clarifications were made in the posts to make it clear I wasn't targeting or accusing anyone, but just issuing a warning of a potential position someone could adopt (see italicized bolded text in my previous posts reproduced below). 

We argue/refute/critique other mistaken positions that forum members here do not hold all the time (i.e. atheist evolution), and technically that is not a strawman argument.

And I did observe this position in a family member, as bolded in green in the post below, so in truthfulness it cannot be said that "absolutely no one" holds this error. Maybe no one here at this moment holds this position, but those outside of this specific forum have.

To be clear, my meaning of position you quote above (underlined text) was re-phrased/further clarified in the post reproduced below (also underlined text). I meant the red text to be referring to the same position. Is it understood that these two statements were referring to the same position, or did you think I was referring to two different positions between these two posts?

Not trying to be confrontational, just want to sort this out.

With all due respect Ladislaus, I disagree. I'm not sure you understood the post. My meaning was that it would be a mistake to assume that St. Thomas was wrong on some topics/many topics just because he was wrong on one topic. And I clarified in the post that I wasn't accusing the poster responded to of this error, but just stating it generally as a direction to avoid. Therefore, this statement was not meant to be interpreted as a refutation of the poster (or anyone else here), and I acknowledged that the poster didn't present, say, or do what I was critical of. It just was meant as a well-intentioned general warning due to personal experiences. 

And with regard to the reality of someone falling prey to the false thought that "a mistake in one topic means by default an mistake in other topics",  I've seen it happen in real life. I've observed the unfortunate case of a family member realizing that St. Thomas was in error about the Immaculate Conception, and then illogically rejecting or becoming suspect about everything St. Thomas said or did. They then rejected any kind of scholastic theology concepts and relied only upon subjective feeling, leading to very strange decision making. I disagree with this, and I think both of us would heartily agree that this kind of progression is a big mistake.

From what I understand that is correct; if I recall St. Bernard of Clairvaux also had somewhat different ideas regarding the Immaculate Conception at one time. It's possible they were wrong in other areas too. However, without critical examination of the individual arguments, I think we must be careful when assuming that a mistake in one area means by default an error in others, as that could easily become a "slippery slope" (not saying you are doing this, but just saying it generally).

Again with respect Ladislaus, as the previous posts reproduced below show, I never did infer guilt or accuse anyone here on the forum of the position you are referring to above. 

Surely, you must think "someone" holds it, since you've gone to great lengths to "refute" the position.  Why else would you waste the time?

St. Thomas wasn't infallible ... that's the bottom line.