24. Clavius, who wrote in 1581:Hmmmmm ... this is a difficult one. Nevertheless, I shall stick my neck out and suggest that the red flag went up when I spotted a poisoning of the well; and the green flag is for a woeful appeal to authority.
Both [Copernicus and Ptolemy] are in agreement with the observed phenomena. But Copernicus's arguments contain a great many principles that are absurd [ding, ding, ding!]. He assumed, for instance, that the earth is moving with a triple motion . . .[but] according to the philosophers [ding, ding, ding!] a simple body like the earth can have only a simple motion. . . . Therefore it seems to me that Ptolemy's geocentric doctrine must be preferred to Copernicus's doctrine.
This wasn't really true by 1581. Ptolemaic models had to assume "epicycles," orbits within orbits, to account for the motion of the planets other than Earth. That is, their motions weren't "proper" either. They wheeled about invisible foci for reasons utterly unknown. Thus, the Ptolemaic system was the one unnecessarily multiplying conjectural elements, in Occam's Razor terms. So you can add the fallacy of "false premise."