A friend of mine once told me a simple story: as a teenager he found out that as his body grew and aged, many of his body’s cells would die and be replaced. He found it a little scary to think that his body would change from now to some different future version of himself. Then he thought—you can change out hard drives and even memory sometimes from working computer applications. So it’s really not so odd that happens to the body too. As with the application, a person’s consciousness continues on.
That teenage revelation wipes away centuries of philosophical speculation about what makes for personal identity and mind-body duality. My friend was quite a smart guy, but that wasn’t the point. The issue was that he had a model for thinking about those issues, and that model simply hadn’t been available earlier.
Earlier generations thought about something called soul, but they had a hard time coming up with a description of what that was. They knew it was different (one thinks of medieval paintings where the soul departs as a puff of smoke from a dying body), but there was nowhere to put it. They needed God or some other ineffable external answer to explain it. Science wasn’t much help, because there was no physical organ that could be identified with the soul. However today we are confronted regularly with software processes (without physical manifestation) running on execution environments. While there is a lot we still don’t know about how the brain works, there is no question that consciousness is such a system. Soul, in that sense, is real—despite persisting confusion on the subject.
You can push this further. Plato worried about forms, the abstractions we use to understand reality. In what sense are they real objects? We use them, but generalities by definition can’t be represented by specific physical objects. That’s the same issue. Any software system has internal objects that it operates upon. Those are perfectly real within the operation of the application, but they have no physical presence. There is a lot still to be learned about the objects of consciousness, but you don’t have to wonder about where to look.
That leads to many interesting questions for both philosophy and science. What can we say about the different classes of objects of thought? What is specifically human? Which of those objects are universally human (what is beauty?), what are hereditary but not universal, what are purely personal, as we each classify our experience. Maybe it’s not the objects but the way of distinguishing them that’s universal? (A child can learn what a dog is from very few examples.) What exactly is unique about the cerebral cortex, and to what extent is it a blank slate at birth? Is it possible that we are actually loading the equivalent of DNA-encoded software!?
To continue, another area where science helps with patterns of thought is probability. We don’t like to think that way, but life is all about probabilities. Quantum mechanics tells us that even physical reality is in fact (at least at a microscopic level) indeterminate. All you can say is that a quantum object may be in one of a number of states with given probabilities. The point here is not that quantum mechanics itself governs our daily lives—it usually doesn’t. But the world requires much more probabilistic mindset than we like to think.
We want badly to live in a world of causality, where we can organize our lives about “this does that”. When someone gives us probabilities, we tend to react by taking the most probable item to be a sure thing. And when causality breaks down we’re uncomfortable. I think about the novel “The Goldfinch” where a particular immoral act ends up having good consequences, and the narrator announces that morality is a sham.
The world we live in is fundamentally probabilistic, and that affects many classical concerns. Essentially all discussions of freewill and predestination tacitly assume that causality is straightforward. In fact not even an all-powerful God can know exactly what is going to happen. A human being’s current state includes everything in memory and all current impulses, conscious or unconscious. What happens as a result of all of that is not only phenomenally complicated, it is fundamentally non-deterministic.
The same kind of reasoning applies in many different areas—morality or political theory, say. Much as we would like to live in a world where we can identify absolute good, that’s just the wrong model for reality. The best we can do is probabilities in particular circumstances.
Finally, quantum mechanics is also an example of how we can get deluded by inappropriate application of scientific models. All of the endless discussions of multiple universes and alternative realities are unsubstantiated nonsense. When a quantum object is described as being in one of a number of possible states (because we haven’t checked yet), that doesn’t mean those potential states are all real. It’s a trick of language—an unobserved state is not a state, it’s just part of a mathematical model for what might or might not happen. There is no real state until a result is observed. There are no parallel universes where all those other possible states are real. There is no inconceivable infinity of parallel universes, with a new one created every time there is an option of outcomes created somewhere.
Similarly there is no inconceivable infinity of parallel universes where past moments from everywhere are somehow preserved and active. Time travel, however intriguing, is imaginary. It’s not just that we don’t know how to do it. It’s that the past and the future simply don’t exist!