Thomas E. Woods, Jr., in How the Catholic Church Built Western Civilization, credits the church as being the primary sponsor of western science throughout most of the church’s existence. His point is valid, though many might find his presentation very economical with the truth. With a view that everything in the universe was interconnected, the church was content to ascribe the plague to sin. The church’s interest in science had something to do with Easter. I’ll get to that after a small diversion to relate this topic to one from a recent blog post.

Catholic theologians, right up until very recent times, have held a totally holistic view, seeing properties and attributes as belonging to high level objects and their context, and opposing reductionism and analysis by decomposition. In God’s universe (as they saw it), behavior of the parts was determined by the whole, not the other way around. Catholic holy men might well be seen as champions of “Systems Thinking” – at least in the popular modern use of that term. Like many systems thinking advocates in business and politics today, the church of the middle ages wasn’t merely pragmatic-anti-reductionist, it was philosophically anti-reductionist. I.e., their view was not that it is too difficult to analyze the inner workings of a thing to understand its properties, but that it is fundamentally impossible to do so.

Santa Maria degli Angeli, a Catholic solar observatory

Unlike modern anti-reductionists, whose movement has been from reductionism toward something variously called collectivism, pluralism or holism, the Vatican has been forced in the opposite direction. The Catholics were dragged kicking and screaming into the realm of reductionist science because one of their core values – throwing really big parties – demanded it.

The celebration date of Easter is based on pagan and Jewish antecedents. Many agricultural gods were celebrated on the vernal equinox. The celebration is also linked to Shavuot and Passover. This brings the lunar calendar into the mix.   That means Easter is a movable feast; it doesn’t occur on a fixed day of the year. It can occur anywhere from March 22 to April 25. Roughly speaking, Easter is the first Sunday following the first full moon after the spring equinox. To mess things up further, the ecclesiastical definitions of equinox and full moon are not the astronomical ones. The church wades only so far into the sea of reductionism. Consequently, different sects have used different definitions over the years. Never fearful of conflict, factions invented nasty names for rival factions; and, as Socrates Scholasticus tells it, Bishop John Chrysostom booted some of his Easter-calculation opponents out of the early Catholic church.

Science in the midst of faith, Santa Maria degli Angeli

By the 6th century, the papal authorities had legislated a calculation for Easter, enforcing it as if it came down on a tablet. By the twelfth century, they could no longer evade the fact that Easter had drifted way off course.

Right around that time, Muslim scholars had just  translated the works of the ancient Greek mathematicians to Latin (Ptolemy’s Almagest in particular). By the time of the Renaissance, Easter celebrations in Rome were gigantic affairs. Travel arrangements and event catering meant that the popes needed to plan for Easter celebrations many years in advance. They wanted to send out invitations specifying a single date, not a five week range.

Sketch from Bianchini’s 1703 “De nummo.”

Science appeared the only way to solve the messy problem of predicting Easter. And the popes happened to have money to throw at the problem. They suddenly became the world’s largest backer of scientific research – well, targeted research, one might say. John Heilbron, Vice-Chancellor Emeritus of UC Berkeley (who brought  me into History of Science at Cal) put it this way in his The Sun in the Church:

The Roman Catholic Church gave more financial support to the study of astronomy for over six centuries, from the recovery of ancient learning during the late Middle Ages into the Enlightenment, than any other, and, probably, all other, institutions. Those who infer the Church’s attitude from its persecution of Galileo may be reassured to know that the basis of its generosity to astronomy was not a love of science but a problem of administration. The problem was establishing and promulgating the date of Easter.

The tough part of the calculation was determining the exact time of the equinox. Experimental measurement would require a large observatory with a small hole in the roof and a flat floor where one could draw a long north-south line to chart out the spot the sun hit on the floor at noon. The spots would trace a circuit around the floor of the observatory. When the spot returned to the same point on the north-south line, you had the crux of the Easter calculation.

Solar observatory detail in marble floor of church

By luck or divine providence, the popes already had such observatories on hand – the grand churches of Europe. Punching a hole through the roof of God’s house was a small price to pay for predicting the date of Easter years in advance.

Fortunately for their descendants, scientists are prone to going off on tangents, some of which come in handy. They needed a few centuries of experimentation to perfect the Easter calculation. Matters of light diffraction and the distance from the center of the earth to the floor of the church had to be addressed. During this time Galileo and friends stumbled onto a few work byproducts that the church would have been happier without, and certainly would not have invested in.

Gnomon and meridian, Saint-Sulpice, Paris

The guy who finally mastered the Easter problem was Francesco Bianchini, multidisciplinarian par exellence. The church OK’d his plan to build a meridian line diagonally across the floor of the giant church of Santa Maria degli Angeli in Rome. This church owes its size to the fact that it was actually built as a bath during the reign of Diocletian (284 – 305 AD) and was then converted to a church by Pope Pius IV in 1560 with the assistance of Michelangelo. Pius set about to avenge Diocletian’s Christian victims by converting a part of the huge pagan structure built “for the convenience and pleasure of idolaters by an impious tyrant” to “a temple of the virgin.”

Bianchini’s meridian is a major point of tourist interest within Santa Maria degli Angeli. All that science in the middle of a church feels really odd – analysis surrounded by faith, reductionism surrounded by holy holism.