The Latin rite of the Catholic Church is today celebrating the feast of St. Robert Bellarmine (1542-1621), a Renaissance Jesuit and cardinal, who most notoriously was one of the Inquisitors who condemned Giordano Bruno to be burned at the stake in 1600 and was involved in the first summoning of Galileo Galilei in 1616 to Rome on orders from Pope Paul V. This summons was not exactly a full-bore trial. Rather, Bellarmine wanted to inform Galileo that the Congregation of the Index was about to condemn the heliocentric model of Copernicus by placing this Polish clerics famous book On the Revolutions of the Celestial Spheres on the Index of Forbidden Books. Given that upcoming condemnation, Bellarmine told Galileo that Copernican theories could no longer be defended or held, although Catholic astronomers could continue to discuss heliocentrism as a mathematical fiction.
On the later election Maffeo Cardinal Barberini as Pope Urban VIIIwho was both a friend of Galileo and had opposed Bellarmines condemnation of heliocentrism in 1616Galileo ventured to propose the Copernican model once more in his epochal Dialogue between the Two Chief World Systems of 1632, which itself led, as everyone knows, to his condemnation by the Inquisition a year later, after which he spent the rest of his life under house arrest.
Although Bellarmine was long dead by that time, his earlier involvement in Copernican controversies has inevitably fused his reputation with the sorry history of Catholic obscurantism, a reputation which is even more besmirched because of his direct involvement in Brunos trialwho was also condemned for his cosmological views.
Part of what makes both cases so dismaying is the way both popes and Inquisitors had not read their Thomas Aquinas with proper thoroughness. I am thinking especially of this passage from Thomass commentary on Aristotles tractate On the Heavens , where Thomas urges caution in accepting Aristotles and Ptolemys geocentrism (all italics added): The suppositions that these men [Ptolemaic astronomers] have invented need not necessarily be true: for perhaps, while they save the appearances under these suppositions, they might not be true . For maybe the phenomena of the stars can be explained by some other schema not yet discovered by men (Book II, lecture 17).
The churchmen of Galileos day could perhaps be excused from knowing this text, based on its relative obscurity and on the fact that Thomass commentary is considerably longer than Aristotles original tract. But Thomas also says something roughly similar in a much more accessible text, his Summa theologiae : Reason can be employed in another way, not as furnishing a sufficient proof of a principle, but as confirming an already established principle, . . . because thereby the sensible appearances of the heavenly movements can be explained; not, however, as if this proof were sufficient , for some other theory might [also] explain them ( S.T. I q. 32, a. 1, ad 2).
Read and weep.