Nicolaus Copernicus

Mikolaj Kopernik (Nicolaus Copernicus) (1473-1543) was a Polish astronomer and physician, who hypothesized that the earth went around the sun.

Unfortunately, Copernicus is far too early to be considered in Father Kneller's book, but Dr. Walsh has this very enlightening paragraph:

A hundred years before Galileo's time Copernicus went down to Italy to study astronomy and medicine, and when his book was published it was dedicated to a Pope. Copernicus himself was a faithful churchman all his life, came near being made a bishop once, and kept the diocese in which he lived, and in which his personal friend was bishop, in the fold of the Church in spite of Luther and the religious revolt all around it in Germany.
[Walsh, The Popes and Science 17-18]

Copernicus, like Galileo, is a name which appears dozens of times throughout Jaki's writing. Some of his study gets into complexities which (as in the case of Galileo) are not what you may have heard before, of very great importance to those of us who want to know the history of science.

...the historian appreciative only of writings but not of writers, because the latter are not sympathetic to him, will become the prisoner of his own sympathies. He will then take some halfjesting remarks of Buridan and Oresme for a proof that they were not believers but skeptics. Underneath this sleight of hand lies the "dogmatic" conviction that no intelligent individual, let alone an individual creatively intelligent in the sciences, can espouse wholeheartedly basic Christian dogmas. The result is that a Copernicus is turned into a Renaissance man. Such is a transparent device to minimize the support he derived from his Christian faith as he conceived and kept developing his views that opened the way to a truly scientific grasp of the universe, the greatest prize for science.

...

In the early 17th century no full scientific conviction would be carried by the enormous simplification that resulted from the heliocentric arrangement of planets. A chief reason for this lay in the inability of Copernicus to offer more precise predictions of planetary positions than was possible on the basis of geocentric astronomy as set forth in impressive detail and cogency in Ptolemy's Almagest. Copernicus' work could almost appear a mere rewriting of Ptolemy. The idiom, Euclidean geometry, was the same, together with such staple parts of it as epicycles, deferents, and eccentrics, to say nothing of its archaic trigonometry. Also, the data were almost the same. Copernicus added fewer than thirty observations of his own to the hundreds he took from the Almagest. Last but not least, his tools of observation were age-old. The invention of the telescope still lay in the misty future.

Why is it, one may ask, that Copernicus was not anticipated by the Greeks of old? The ready answer that Copernicus was a genius is a mere begging of the question, and all the more so as geniuses were not lacking among the Greeks, and certainly not in the field of astronomy. One of them was Aristarchus of Samos. His method of measuring the absolute sizes of the moon and the sun and their relative and absolute distances from the earth still fill with astonishment any sensitive mind when first exposed to it. No less a genius was Archimedes who made much of that method as he calculated the total number of sand grains that could be accommodated within the sphere ofthe fixed stars, standing for the entire universe. Archimedes meant it to be a teaser, a means for entertaining his royal patron in Syracuse.

Both Aristarchus and Archimedes could have easily preceded Ptolemy by three and two hundred years respectively in writing an essential equivalent to the Almagest. If such is the case, may not one reasonably entertain the possibility that Aristarchus of Samos could not only have written a short Almagest but also a teaser, a heliocentric version of it? As a teaser it certainly would have remained within the perspectives of the great majority of Greek astronomers. They had fully subscribed to the methodology set by Plato. Their learned, intricate combination of circles, arcs, and radiuses were to be offered as so many devices "to save the phenomena." They were means of prediction but in no sense a reflection of reality. The program was a sophisticated resignation, a glittering abdication of search for truth about the physical universe.

...it would be natural to assume that very different religious motivations may have helped Copernicus, as he boldly cast his scholarly lot with heliocentrism. The standard claim that he was a Renaissance man is a cheap red-herring. He was certainly not one of those many Renaissance humanists who poured scorn on science as incompatible with the dignity of "Letters" often reduced to hairsplitting in matters grammatical. He was not known to have engaged in alchemy and in that obscurantist animization of the universe which had Paracelsus, Bruno, and Fludd for its chief promoters. He was in fact at poles removed from the pan-animism which Bruno used as a cover-up for pantheism. ...

Copernicus himself had to muster some saving grace. That the grace in question was strictly religious in character may be surmised from an admission telling for its brevity. It was made in a much applauded book on the astronomical revolution by a sophisticatedly tendencious historian of science, Alexandre Koyré, whom many in a now aging generation of historians of science have been fond of recalling as the master. Koyré's chief aim was to discredit Duhem's claim that medieval science, especially in the form given to it by Buridan and Oresme, grew organically into the science of Galileo. He therefore could not say more about Copernicus' religious conviction than that he was a "good Catholic." Coming as it does from a professed agnostic, fond of the spirit of the French Enlightenment, this brief admission admits enormously much. Not that Koyré would have wished to explain the various possible meanings of being a "good Catholic." In all appearance he wanted the expression to stand by itself That way it could suggest that Copernicus was a good but not necessarily a thinking Catholic. But this is precisely what will not do in the case of a thinker of Copernicus' stature.

Copernicus was, of course, a Catholic of his times. As such he was fond of the fashionable phrases of the day. For some time already and for a while yet, thoughts were presentable only when offered in a verbal garb overdecorated with references to Greek and Latin celebrities. Hence the references of Copernicus to various antique authors in the letter dedicating his De Revolutionibus orbium coelestium to Cardinal Schönberg. Being a good Catholic and in Renaissance times, the Cardinal did not have to think that he might be deceived as was Isaac whom Jacob approached as if he were Esau. The Cardinal expected the Catholic voice to come in Renaissance garb. Instead of the biblical Lord of Hosts, Copernicus spoke of the divine Artificer. Yet Renaissance as the expression could appear, good Catholics of Renaissance times were fully aware of its equally biblical use in the Book of Wisdom (13:2), which they revered as a revealed word of God. But the confidence which Copernicus expressed in the full rationality of the universe could not be referred to Greek and Latin sources. That confidence was the echo of the voice of Athanasius whose "Nicene" creed Copernicus, as a canon of the Cathedral of Frauenburg, recited every Sunday.
[Jaki, The Savior of Science]

There's a lot there - and there's far more to explore, but like Galileo and Duhem and others, I will have to defer a larger study for now.

Also see the Catholic Encyclopedia for more.