ABSTRACT
In 1543, a Polish mathematician, astronomer and physician, Nicolaus Copernicus, published a book that would initiate a revolution in human thought. Copernicus's starting point is made clear in the introduction to the De Revolutionibus, dedicated to Pope Paul III. Nor did the Copernican system, as first proposed, succeed in eliminating the old Ptolemaic devices of epicycles and eccentrics. An astronomical argument against the Copernican view was the objection that stemmed from the apparent differences between earth and heaven. There were arguments against Copernicus that were drawn from both astronomical observations and the best natural philosophy. An argument against the Copernican system is more philosophical than empirical. Tycho Brahe was impressed by Copernicus's mathematical achievements and very sympathetic to his attempts to get rid of the embarrassing Ptolemaic equant. Tycho's system involved a whole series of complex, interacting motions.
