Daly's article certainly favors the idea that heliocentrism was condemned for heresy and the arguments are strong. I won't list them here. The arguments against the condemnation not being infallible were less persuasive. 1. It seemed only to be against Galileo, 2. never specifically said it was heretical (although they admit it was said other places) 3. did not define a doctrine and 4 wasn't addressed to the whole Church. I'm no theologian, nor is it necessary for me to argue in detail against the parsing of words this argument rests on, but even if technically true, the conclusion drawn would be in direct contradiction to the reason for condemnation. Why condemn what isn't heretical? How can a condemnation only apply to one man and no one else and the problem be solved if he abjured? I suppose there may be technical reasons for this opinion, but they don't add up to much. The churchmen discussed the doctrines heliocentrism contradicted and errors it promoted during the trial. Obviously, from discussion within the trial, along with the Bruno Affair and arguments and condemnations against others defending heliocentrism, they considered it all intolerable, an extreme danger to the faith as well as the source of innumerable errors, like reincarnation. This reminds me of Anne Catherine Emmerich's assessment of the false notion of cosmology would be the mother of all heresies.
That Robertson was a liberal has no bearing whatsoever. He concluded, after intensely detailed work, that the condemnation was infallible and Roberts believed in heliocentrism which makes his conclusion all the more plausible.
What's truly interesting is the people who suggest that heliocentrism can't be heresy. That's strange since the entire panel of popes, saints and theologians who expounded on the problems with heliocentrism at the time were extremely erudite and animated about the errors it produced and most notably for them, because it contradicted scripture.
The devil may be in the details, but along with innumerable errors, there's another good reason to abandon heliocentrism: It can't possibly have been so deeply divisive and not be a danger to one's soul.
Yes, I find it much more probable that this decision of the Holy Office is infallible than that Benedict XV's passing comment would be infallible.
There's no question that the Holy Office did intend to address this to the entire Church. What, when the next guy came along teaching the same thing as Galileo, they would then have to issue a new decree? And it does quite clearly teach a doctrine. To me the biggest question is whether a decree of the Holy Office has behind it a sufficient plenitude of papal authority, i.e. the biggest question mark is whether the POPE taught this by virtue of his Petrine office. To me, ratifying a decision from the Holy Office falls a hair short of that.
Nevertheless, I hold it improbable that the Holy Office could err this badly on a matter of such great consequence, and I'm morally certain that they were not in error.
But here's the kicker. If there's widespread and well-founded doubt about whether something is
de fide, then it's not
de fide. In order for something to be held
de fide, it has to be held as certain with the certainty of faith, but (and you have to think about it here a bit) if it's not certain with the certainty of faith that it is certain with the certainty of faith, it cannot be held with the certainty of faith. I believe that geocentrism is OBJECTIVELY
de fide but I also don't hold that to be certain with the certainty of faith due to well-founded and widespread disputes about whether it has in fact been dogmatically defined.
And one last point. In the Holy Office decree, heliocentrism was what was rejected as heresy. Nobody really believes in heliocentrism anymore, where the sun would be the fixed center of the universe. Yet the Holy Office stated that the denial of geocentrism was a grave error (but not quite heretical); it assigned it a slightly lesser theological note than the condemnation of heliocentrism. Of course, infallibility is slightly different than
de fide. I believe that it's possible for a teaching to be infallible even when declaring something to be in error with a lesser note than that of heresy.