Stephen Casper: An Ethical Lesson from Quantum Physics

Stephen Casper,

One of my professors, Boaz Barak, wrote this in a chapter on quantum computing in his textbook:

“If you don’t find the above description confusing and unintuitive, you probably didn’t get it. Please make sure to re-read the above paragraphs until you are thoroughly confused.”

Quantum physics are just weird. Somehow, things can be both waves and particles at the same time, be spread out over many places at once, disappear and reappear somewhere else without traversing the space in between, and display a bizarre entanglement with another particle despite no forces acting between them. It makes no sense how exactly this stuff happens, but, in a metaphysical sense, why would it? These phenomena are only exhibited by very small, very isolated, or very cold things. Meanwhile, Newtonian physics make plenty of sense because we’re used to observing them, and they are reasonably well-embedded into our mental models of the world. We don’t ever directly perceive quantum phenomena, so they don’t make sense to us nearly as easily. Yet we still have quantum theories with all of their valuable explanatory power because when physicists observed these phenomena, they didn’t say “Oh, but that doesn’t make sense. I reject this theory.” Instead, they carefully followed the logic and evidence to very novel conclusions. (Not that they weren’t skeptical at first of what seemed strange—as any Bayesian should be.)

Neil DeGrasse Tyson is known for his quote, “The universe is under no obligation to make sense to you,” and we should think of ethics the same way. I wish it were viewed as bad practice in philosophical contexts to make an argument by bringing up a counterexample which everyday intuition would find repugnant and then suggesting a theory must be wrong because it conflicts with intuition in that particular case (Take the trolley problem for instance.). Arguments that only appeal to intuition are conclusions masquerading as reasons. Humans evolved a selfish, heuristical, shortsighted, and tribal sense of morality. Why should we let our instincts be in charge? Not only would that make moral philosophy a useless process of self-rationalization, it would lead us to make very bad decisions. Some of the most important moral questions of our time are examples of when a natural, intuitive sense of morality and a rational one conflict.

We can be as scientific about morality as any other science, beginning with a set of naturalistic values (I agree with the idea that we should see moral good as pertaining to the welfare of conscious beings) and soberly thinking through the trail of connected questions laying ahead of us, constantly using evidence and checking our bias. That’s much easier said than done, but my point is that we can do better than our intuition. We need to respect logic, be consistent, and take rational conclusions seriously.