Is God a Mathematician_ - Mario Livio [54]
The Mathematician God of Newton and Descartes
As were most people of their time, both Newton and Descartes were religious men. The French writer known by the pen name of Voltaire (1694–1778), who wrote quite extensively about Newton, famously said that “if God did not exist, it would be necessary for us to invent Him.”
For Newton, the world’s very existence and the mathematical regularity of the observed cosmos were evidence for God’s presence. This type of causal reasoning was first used by the theologian Thomas Aquinas (ca. 1225–1274), and the arguments fall under the general philosophical labels of a cosmological argument and a teleological argument. Put simply, the cosmological argument claims that since the physical world had to come into existence somehow, there must be a First Cause, namely, a creator God. The teleological argument, or argument from design, attempts to furnish evidence for God’s existence from the apparent design of the world. Here are Newton’s thoughts, as expressed in Principia: “This most beautiful system of the sun, planets and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being. And if the fixed stars are the centers of other like systems, these, being formed by the like wise counsel, must be all subject to the dominion of One.” The validity of the cosmological, teleological, and similar arguments as proof for God’s existence has been the subject of debate among philosophers for centuries. My personal impression has always been that theists don’t need these arguments to be convinced, and atheists are not persuaded by them.
Newton added yet another twist, based on the universality of his laws. He regarded the fact that the entire cosmos is governed by the same laws and appears to be stable as further evidence for God’s guiding hand, “especially since the light of the fixed stars is of the same nature [emphasis added] with the light of the sun, and from every system light passes into all the other systems: and lest the systems of the fixed stars should, by their gravity, fall on each other mutually, he hath placed these systems at immense distances one from another.”
In his book Opticks, Newton made it clear that he did not believe that the laws of nature by themselves were sufficient to explain the universe’s existence—God was the creator and sustainer of all the atoms that make up the cosmic matter: “For it became him [God] who created them [the atoms] to set them in order. And if he did so, it’s unphilosophical to seek for any other Origin of the World, or to pretend that it might arise out of a Chaos by the mere Laws of Nature.” In other words, to Newton, God was a mathematician (among other things), not just as a figure of speech, but almost literally—the Creator God brought into existence a physical world that was governed by mathematical laws.
Being much more philosophically inclined than Newton, Descartes had been extremely preoccupied with proving God’s existence. To him, the road from the certainty in our own existence (“I am thinking, therefore I exist”) to our ability to construct a tapestry of objective science had to pass through an unassailable proof for the existence of a supremely perfect God. This God, he argued, was the ultimate source of all truth and the only guarantor of the reliability of human reasoning. This suspiciously circular argument (known as the Cartesian circle) was already criticized during Descartes’ time, especially by the French philosopher, theologian, and mathematician Antoine Arnauld (1612–94). Arnauld posed a question that was devastating in its simplicity: If we need to prove God’s existence in order to guarantee the validity of the human thought process, how can we trust the proof, which is in itself a product of the human mind? While Descartes did make some desperate attempts to escape from this vicious reasoning circle, many of the philosophers who followed him did not find his efforts particularly convincing. Descartes’ “supplemental proof” for the existence of God was equally questionable.