This summer’s holiday was spent in Italy – some of it in Rome, where I stood in line for one hour and a half to get into the Musei Vaticani. It was worth the wait. This museum, mostly known for the Sistine Chapel and Rafael’s frescoes, is huge and has treasures on almost any wall. It is quite fascinating to watch the Athens School in the original, for instance.
The items most interesting to me, however, were these two unassuming monters found in the library section, opposite a stand selling postcards. They are mechanical demonstrations of two world systems – the heliocentric system of Copernicus, Kepler, Galileo and Newton, and the geocentric system of Ptolemy and Aristoteles. (After writing this, I have to confess I am a little uncertain about the monter on the left – I am pretty sure it is Ptolemaic, with some modifications. Experts?)

The monters stand there, without sign or commentary, unmentioned on the audio guide that otherwise will tell you about each room in tedious detail. Yet they represent the Catholic church’s loss of scientific legitimacy: As the Church clung to the increasingly untenable position that the Earth was at the center of the universe, scientists increasingly ceased to see the church as a legitimate sponsor or even legitimate actor in scientific endeavors. Science and church split – and what science remained in the church was increasingly limited to increasinly obscure theological interpretation – while science went on to triumph based on what Leonardo da Vinci called “the addiction to experience.”
According to Richard Tarnas (in The Passion of the Western Mind,) a “unique and potent combination of circumstances” led the church to reject the heliocentric hypothesis. Quite a few of the high clerics were ready to accept Galileo’s proposition that the earth rotated and circled around the sun – the Pope was a friend of Galileo, and one cardinal wrote about the necessity to “proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary, and rather admit that we did not understand them than declare an opinion to be false which is proved to be true.” (p. 260ff.)
However, the church (already under pressure from the Reformation) had participated in the elaboration of the spherical theories of Aristoteles and Ptolemy, to the point of assigning responsibility for the movement of some of the planets to specific arch-angels. So, if Galileo (who wrote in vernacular Italian and was of the “vitriolic personality” so often found in innovators) was not necessarily contradicting the bible, he certainly was contradicting centries of increasingly refined theologically founded natural philosphy, and by accepting Galileo’s propositions, the church would have to admit being wrong – hard to do in a climate where the church was also battered by charges of corruption and with a decided lack of enthusiasm for the divine powerty espoused by increasingly numerous charismatic movements.
This rejection of heliocentrism failed, of course. Tarnas again:

That decision caused irreparable harm to the Chruch’s intellectual and spritual integrity. Catholicism’s formal commitment to a stationary Earth drastically undercut its status and influence among the European intelligentsia. The Church would retain much power and loyalty in the succeeding centuries, but it could no longer justifiably claim to represent the human aspiration toward full knowledge of the universe. […] In Galileo’s own forced recantation lay the Church’s own defeat and science’s victory.

And, quietly and unassumingly the little monters stand, silent witnesses to the dangers of believing theory in the face of evidence.