Bizarrely enough, the one attempted comment I made at Yglesias that I bothered to copy before posting actually got through anyway. You can find the comment here, but I’ll reproduce it below.
“I just read Kuhn’s book and his account sounds different from yours. It did mention neo-Platonism, but I don’t recall it saying Copernicus was a member of any cult as a young man. Copernicus did not set out to abolish epicycles, he had to include a lot of them to make the predictions of his model fit the data. And the problem with his theory wasn’t just that orbits are ellipses rather than perfect circles like he assumed, it was also the case that a lot of the old data he was relying on was inaccurate and we needed new and better data from Tycho Brahe (still a Ptolemaist who had the sun go around the earth while most planets went around the sun) to get an accurate picture.”
To elaborate on what I wrote above, the innovation produced by Ptolemy that Copernicus really rejected was the equant. He rejected it because he (incorrectly) insisted on uniform circular motion and the way he replaced it was with epicycles, which Yglesias incorrectly states that Copernicus abolished! He seems to be repeating the myths that Kuhn set out to debunk. Kuhn also noted that Copernicus’ epicycles were of the “minor” variety, but I think that distinction may post-date the heliocentric model.
UPDATE 06/23/2018: The above link to Yglesias doesn’t work. His post is now here, with no comments.
Entitled to an Opinion 
October 17, 2011 at 1:30 am
i keep forgetting to copy before posting comments, too -this tends to kill me these days on OB. I think my facebook privacy setting hides my yglesias comments.
I’ve now been pretty much marginalized to your comment section and my low traffic blog through rising barriers in other venues.
October 17, 2011 at 7:35 pm
I guess that’s a loss for you and a gain for me.
October 18, 2011 at 2:59 am
hehe
October 17, 2011 at 9:10 am
Matthew Yglesias frequently act to support the theory that Harvard’s undergraduate program is more about networking than education.
And he probably learned his economics from Greg ‘whatever the right needs me to say’ Mankiw.
October 17, 2011 at 9:58 am
Naw, his economics seem to me to be in the same left-technocrat stream as DeLong, Romer, Sumner as opposed to the right-technocrat stream of Mankiw, Feldstein, etc.
October 17, 2011 at 7:36 pm
I agree with you on where he fits, but Barry may be literally correct. Mankiw teaches a lot of undergraduates, but that doesn’t mean they end up being Mankiw-clones.
October 20, 2011 at 8:40 pm
Apropos of “neo-Platonist cults” – well, Neoplatonism was as much a part of the intellectual commonplaces of the sixteenth century as Marx, Freud, and Keynes are of today’s. It no more constituted a “cult” than the followers of those dubious thinkers are considered to constitute today.
The revival of the study of Greek in the West began in the mid-fifteenth century in Italy, when Greek scholars like Cardinal Bessarion and Gemistus Pletho came there. Cosimo de Medici began collecting Greek manuscripts and had his house scholar, Marsilio Ficino, begin translating Plato from Greek to Latin. When a manuscript of the Corpus Hermeticum – the writings attributed to the legendary Hermes Trismegistus – was found, Cosimo ordered Ficino to set aside Plato, and begin on the Hermetica. The latter were then (mistakenly) considered more ancient than the works of Plato, although in fact they dated in their present form only from the first and second centuries A.D. Hermeticism and ancient Neoplatonism are not exactly the same, but they merged in what historians now call Renaissance Neoplatonism. This was an immensely influential current in the history of ideas for more than two hundred years, dying out only in the late seventeenth century. See for further explanation Dame Frances Yates’s “Giordano Bruno and the Hermetic Tradition” and D.P. Walker’s “Spiritual and Demonic Magic from Ficino to Campanella.”
All that Copernicus did was to cite the Hermetica as an ancient source supportive of heliocentrism. Great store was then set upon the knowledge of ancient languages and literature, and no work of scholarship would have been taken seriously without copious references to the Greek and Latin classics. Copernicus was certainly not an occult heliocentrist in the way that Bruno or Campanella were, but he did draw from the same streams of thought that they did. Let us recall that Bruno was burnt at the stake as a relapsed heretic in 1600, only 16 years before Cardinal Bellarmine first warned Galileo against holding or defending Copernicus’s heliocentric ideas, and 33 years before Galileo was sentenced to perpetual imprisonment (commuted to house arrest) by the Inquisition.
The scientific and religious aspects of heliocentrism were understandably confused, because Brunonian heliocentrism was quite definitely motivated by heterodox religious views, much less so by empirical ones. It is worth noting that non-scientific motivations for the promotion of certain seemingly scientific propositions are just as important today as they were in the seventeenth century. Consider the claims of “global warming,” which are driven as much or more by political and economic ambition than they are by empirical evidence. Consider the assertion of Boasian social anthropology that race is only a social construct and there is no human biological diversity. These are the orthodoxies of our time, maintained for reasons of state, and not for those of science. Dissenters are no longer burnt at the stake – it suffices that their reputations are laid waste and their careers destroyed. Eppur si muove.
October 20, 2011 at 9:37 pm
Yeah, I’ve heard about Bruno and the mistaken belief that he was some martyr for science.
Many of the policies promoted in response to global warming are similar to policies already favored for other reasons, but at this point it seems like the evidence for the occurrence of warming is quite solid, and to borrow from another thread here it has good “micro-foundations” in physics.
October 20, 2011 at 10:58 pm
The evidence for warming may be solid, but for its anthropogenic origin, not so solid. The icecaps on Mars are observed to be shrinking; since no one is driving SUVs, operating coal-fired electric utilities, raising flatulent cows, or engaging in any of the other activities disfavored by Al Gore, the question to be answered is – what else might be causing it? Increased solar irradiance is the most likely explanation; and if it is warming Mars, it must à fortiori be warming the earth. The problem with this explanation is that Gore & Co. cannot command the sun to cool down, nor make any money in the process of trying. Since their interest is in social control and rent-seeking economics, an explanation that enables them to command and to tax or otherwise to parasitise human beings – particularly citizens of the United States – is in order. Hence, the popularity of claims for anthropogenic global warming.
If anthropogenic global warming is so obvious, why were there efforts to sweep evidence for the Mediæval Warm Period under the carpet? Why did the leaked Climategate e-mails contain such proud boasting, in the presumed confidence of the insiders, of techniques developed for cooking the data to suggest what their authors wished to suggest? I am far from being a climate scientist, but it is obvious that if simply telling the truth was sufficient to support their theories, there would have been no reason for such fabrications. Their behavior in this regard has been quite sufficient to impeach their testimony.
October 22, 2011 at 11:00 pm
Just because the sun causes warming, doesn’t mean other factors are not also causing it. And as David Friedman noted, even that is fairly irrelevant.
Guilty men are framed all the time. In fact they are most at risk of framing. If one takes Alan Dershowitz’ 13 Rules seriously rather than as just amusing cynicism, it would be about what’s expected.