Pierre Duhem, To Save the Phenomena: An Essay on the Idea of Physical Theory from Plato to Galileo
The University of Chicago Press, 1969, 117 pgs.
Summary: Pierre Duhem (1861-1916) was a French physicist and developer of the history of the philosophy of science. He was also a strong Roman Catholic and a humbling thorn in the flesh for his contemporaries in the French academy. Apparently, he delighted in piquing them.
The common historical narrative is that Galileo was an enlightened scientist who was censored and cowed by the bigoted and reactionary Catholic Church. There is of course some truth to the myth or it wouldn’t have stuck. Galileo was a brilliant scientist and the Catholic Church was often bigoted and reactionary, but. . . and it’s a significant conjunction, Galileo (1564-1642) and his cohorts were making some claims about natural philosophy or science that were irrational, and Bellarmine (1542-1621), other Catholics, and Osiander (a mostly Protestant—c.1496-1552) attempted to correct their unreasonableness.
The basic issue is that the Greek philosophers had “proved” there were two forms of physics—earthly and celestial. The celestial sphere was unchanging and the earthly sphere allowed for change and flux. While the rules that governed these two physics were analogues, they operated differently. Plato’s system was the most rigid, but Aristotle’s was similar. This philosophical doctrine cohered to Christian theology, because the Bible clearly teaches a difference between heaven and earth. Greek physics was then modified and incorporated into Christian hermeneutics and theology with little or no ado for about a thousand years (cf. review of the Lewis’ Discarded Image). Aristotle would not have claimed and likely barely recognized the system that developed.
Prior to the Renaissance astronomy as a science was merely a hypothesis that described and helped predict observable phenomena. As long as one merely attempted a tentative hypothesis as an explanation of all known phenomena, no one was concerned about which theory one held to if there was no direct contradiction with a known truth. Generally within the church, Aristotelian metaphysics (ontology, epistemology, cosmology, etc.) was understood as truth and God’s Word was interpreted through the divided Greek physics. As physics, mathematics, and optics matured, more and more evidence or observation of phenomena accumulated that the physics of the celestial was identical to the physics of the earth.
Galileo rejected the Aristotelian divided physics and the metaphysics because of his observation of changing phenomena in the celestial realm. While this is bold and important, he also assumed that his hypothesis for explaining the phenomena was true. In his mind if his hypothesis had more explanatory power of his experience than the Aristotelian model, his hypothesis must be true.
“Galileo’s notions of the validity of the experimental method and the art of using it . . . conceive[d] of the proof of a hypothesis in imitation of the reduction ad absurdum proofs that are used in geometry. Experience, by convicting one system of error, confers certainty on its opposite” (109).
Such a view led to accurate critiques by contemporaries like this: “no matter how numerous and exact the confirmations by experience, they can never transform a hypothesis into certain truth, for this would require, in addition, demonstration of the proposition that these same experiential facts would flagrantly contradict any other hypothesis that might be conceived” (111).
Two misadventures were occurring at the same moment: for the first time true science, a observable united physics, and the official position of the church were at loggerheads. Second, the scientists in rightly critiquing the false physics of the church stepped beyond the limits of science into the realm of absolute truth instead of hypotheses and probability. Both parties were denying the truth, and both were destroying the possibility of reconciliation as long as they clung to a provable falsehood. The fissure between religion and natural philosophy/science occurred over both parties’ misunderstanding the truth of things.
Duhem stops here, but I want to add the following:
Prior to the Enlightenment a modified Aristotelian/Platonic metaphysics (ontology, epistemology, cosmology, etc) provided the shared background for theological and philosophical discussion. This included natural philosophy and science. The Greek metaphysics was simply assumed by the church because it cohered reasonably well with the earthly and heavenly division described in the Bible and no one was really holding to any other position. It is important to note that several passages of Scripture do not support a divided physics (Matt. 2:9; 2 Peter 3:7, 12; Ps. 102:26-27) within observable creation.
When the natural philosophers discovered that the physics of the earthly and celestial realms were identical, the discovery discredited the epistemological or metaphysical framework of both the church and Aristotle. Historically the epistemological vacancy was filled up with developing forms of materialism in Epicureanism and Stoicism among the emerging natural philosophers and academy.
The general tenor of Enlightenment thought, materialism, excluded the possibility of God and God speaking; thus the scientific and religious fissure became axiomatic. Most theologians, both Catholic and Protestant, understood their options as holding to a metaphysics that denied known physical phenomena or attempting to create some sort of working theological system within the framework of Enlightenment thought. Compromise with Enlightenment thought was progressively corrosive leading to the different forms of liberalism. Many Christians faced with an untenable “orthodoxy” and a soul-killing liberalism chose fideism or pietism, thus undermining the role of right reason as a means to understand reality.
Benefits and Detriments: The book lacks sympathy or much information about the Protestant response, but I lack the historical background to critique Duhem on his brief consideration of the Protestants.