I took a course at Carleton University on the philosophy of religion. Our final exam consisted of writing two essays on a variety of topics we’d covered during the semester.
I chose to analyze Blaise Pascal’s pragmatic argument for reasons to believe in God. I like Pascal’s mathematical approach to beliefs. However, in my opinion, the argument breaks down because we don’t agree on what should be plugged into the formulas.
The second essay focused on the inconsistency between God being all-knowing and the human ability to do otherwise (libertarian freedom). The argument goes something like this: If God knows everything including the future, then the future is pre-determined. Thus, humans are not free. This view is difficult to get around but I do my best to critique it in the essay.
I added a few quotes from Sean Carroll’s book that are relevant to this second topic.
As far as determinism is concerned, however, the existence of chaos could not possibly be more irrelevant. Laplace’s point was always that perfect information leads to perfect prediction. Chaos theory says that slightly imperfect information leads to very imperfect prediction. True, and it doesn’t change the picture the slightest bit. Nobody in their right mind was ever under the impression that we would be able to use Laplace’s reasoning to build a useful prediction-making device; the thought experiment was always a matter of principle, not one of practice.
But when we observe a system, it seems to behave randomly, rather than deterministically. The wave function “collapses,” and we can state with very high precision the relative probability of observing different outcomes, but never know preciscly which one it will be.
There are several competing approaches as to how to best understand the measurement problem in quantum mechanics. Some involve true randomness, while others (such as my favorite, the Everett or Many-Worlds formulation) retain complete determinism.
The momentary or Laplacian nature of physical evolution doesn’t have much relevance for the choices we face in our everyday lives. For poetic naturalism, the situation is clear. There is one way of talking about the universe that describes it as elementary particles or quantum states, in which Laplace holds sway and what happens next depends only on the state of the system right now. There is also another way of talking about it, where we zoom out a bit and introduce categories like “people” and “choices.” Unlike our best theory of planets or pendulums, our best theories of human behavior are not deterministic. We don’t know any way to predict what a person will do based on what we can readily observe about their current state. Whether we think of human behavior as determined depends on what we know,
There’s no reason to accept libertarian freedom as part of the real world. There is no direct evidence for it, and it violates everything we know about the laws of nature. In order for libertarian freedom to exist, it would have to be possible for human beings to overcome the laws of physics just by thinking.
The Big Picture – Sean Carroll