A few years ago, a group of us heard a remarkable talk on the brain as a machine, where the speaker aggressively argued that our minds are nothing but a loose mechanistic confederation of parts competing against one another. As we were leaving, a friend of mine remarked to him, "In twenty years I have not met such a man of faith." The speaker, a well-known professor from MIT and a hard-core atheist, recoiled at her remark in some shock. "Yes," she added, "you are so sure you are right!"
Most of my scientific acquaintances, both theists and atheists, are persons of deep but unexamined faith. Recently, on a radio talk show, I referred to a fellow participant as a man of faith. "I don't believe in anything!" he protested. "Of course you do," I countered. "You believe in a rational universe where the laws of nature always work." Experience teaches us that the laws of nature are pretty dependable, so it is easy to take this on board as a tacit belief.
Perhaps surprisingly, "laws of nature" in the modern sense is a relatively recent concept. The expression did not enter our English vocabulary until the work of Robert Boyle and Isaac Newton in the seventeenth century. Kepler, for example, didn't use the expression. What we refer to as Kepler's laws were not singled out and labeled as such until well into the eighteenth century. His laws, prototypes for laws of nature, are a good demonstration of the fact that such laws are human artifacts, man-made and subject to revision. Kepler's third law states that the ratio of the cube of a planet's average distance from the sun to the square of its period of revolution is a constant, but Newton's work showed that the ratio is not a constant but a quantity dependent on the mass of each planet.
As Einstein said, in a statement that can equally refer to the laws of nature, "The sense experiences are the given subject matter. But the theory that shall interpret them is man-made, never completely final, always subject to question and doubt."
Laws like Kepler's, or Newton's famous laws of motion, can be classed as epistemological statements based on what we have gleaned observationally. Most scientists will, after a little contemplation, agree that these laws are man-made. But they will likely add that such formulations are approaching some deeper, inviolate laws of nature that exist whether or not we fully comprehend them. …