Philosophy

In our last discussion of morality and science, an interesting argument was raised in the comments (by rbd and then in more detail by Ben Finney), concerning an analogy between morality and health. Sam Harris has also brought it up. It’s worth responding to because it (1) sounds convincing at first glance, and (2) has exactly the same flaw that the morality-as-science argument has. That’s what a good analogy should do!

If I can paraphrase, the argument is something like this: “You say that morality isn’t part of science because you don’t know what a `unit of well-being’ is — it’s not something that could in principle be measured by doing an experiment. But one could just as easily say that you don’t know what a `unit of health’ is, and therefore medicine isn’t part of science. The lack of some simple measurable quantity is a simplistic attack against a sophisticated problem.”

This gets right to the point. Because, in fact, I don’t know what a “unit of health” is, which is why medicine is not — solely — part of science.

Let me explain what I mean. Obviously we use science all the time when it comes to medicine. Similarly, we should be very ready to use science when it comes to morality — it’s an indispensable part of the endeavor. But in both cases there is a crucial component that lies outside the realm of science.

Here’s how we do medicine, in a cartoonishly simplified version that is nevertheless good enough for our present purposes. First, we decide what we mean by “healthy.” Then, we use science to try to bring it about.

That first step is not science, no matter how much science might be involved in the definition. Various measurable quantities certainly belong to the realm of science — height, weight, pulse, blood pressure, lifespan, time in the 40-yard dash, etc. But what we decide to label “healthy” is irreducibly a human judgment, not an empirical measurable. Some people might think that extreme thinness is part of being healthy, while others might prefer a more robust physique. Some people might define health as the state that maximizes life expectancy, while others might put more emphasis on quality of life even at the expense of total years. It matters not a whit what people actually think, of course — even if everyone in the world agreed on what “healthy” meant, it would still be a judgment rather than an empirical measurement. If one contrarian person came up with a different definition, they wouldn’t be “right” or “wrong” in the conventional scientific sense. There is no experiment we could do to answer the question one way or another.

In the real world, we more or less agree on what constitutes health, so the non-empirical status of this choice isn’t treated as a crucially important philosophical problem. (At least, until you start reading the literature on disability studies, and you realize that what you thought was obvious maybe is not.) We agree on what health is, and we set out to achieve it, and that second part is very much science.

Morality is exactly the same way, although with somewhat less unanimity in the first step. We agree (or not) on what morality is, and once we do the process of achieving it is very much a scientific issue, in the broad-but-perfectly-valid definition of “science” as “an understanding of how the world works based on empirical data.” Once again, it doesn’t matter whether we agree or not, because that first step is a decision we human beings make, not something we measure out there in the world.

While both health and morality are human choices rather than empirically measurable quantities, they certainly aren’t random choices. Human beings aren’t blank slates; we have preferences. Most of us would prefer to live longer and be free of aches and pains; these preferences feed into how we choose to define “health.” Likewise for morality. But “we broadly agree on X” is not, and never will be, the same statement as “X is a scientific truth.” Understanding our preferences, turning vague impulses into precise statements, constructing logical frameworks based on them — that’s what the philosophy of medicine/morality is all about.

The case of morality is actually much more difficult than the case of health, because most interesting moral questions involve tradeoffs between the interests of different people, not only the state of one individual. So even if we could do experiments to establish a unique map between mental states and human well-being, we wouldn’t really be any closer to reducing morality to science. All very fun to think about, though.

Tim Maudlin is writing a two-volume introduction to the philosophy of physics, and I was fortunate enough to get a peek at a draft of Volume One, about space and time. There is one anecdote in there about Leibniz’s objections to Newtonian physics that is worth passing along. This came up in the course of the Leibniz-Clarke correspondence.

Leibniz was quite fond of proclaiming overarching a priori principles. Perhaps the most famous/infamous is the Principle of Sufficient Reason, which states that everything that happens does so for some good reason. But there was also the Principle of Identity of Indiscernibles, which states that if two things have all the same properties, they are really the same thing. Sounds reasonable enough (although one might worry what qualifies as a “property”), but it can get you in trouble if you take it too far.

Remember that Newton believed in absolute space — a rigid three-dimensional set of points that forms the arena in which physics takes place. Leibniz, on the other hand, claimed that space should be thought of purely in terms of relations between different points, without any metaphysical baggage of “absoluteness.” (From a modern perspective, Leibniz was closer to correct, given Galilean relativity; but once we allow for spacetime curvature in general relativity, the relational view becomes less useful.)

So far, so good. The weird part, to modern ears, comes in when we consider Newtonian cosmology. In order to explain matter in the universe, Newton departed from the strict consequences of his Laws of Motion. Instead, he imagined that empty space existed for an infinite period of time, before eventually God decided to create matter in it.

That’s the part Leibniz couldn’t go along with. He didn’t believe God would work that way, for reasons that amount to what we would now call the translational invariance of space. If God is going to create all this matter in empty space, Leibniz reasons, He has to put it somewhere. But where? Every point is equally good! Therefore there can’t be any “sufficient reason” to create it in one place rather than in some other place. Therefore there must be a deep metaphysical flaw at the heart of Newton’s theory. Interestingly, he didn’t go for “matter has been around forever,” but instead came down on the side of “there is no such thing as absolute space.”

Maybe he was worried about Boltzmann Brains?

No, it’s not. Don’t be alarmed: nobody is claiming that dark matter is supernatural. That’s just the provocative title of a blog post by Chris Schoen, asking whether science can address “supernatural” phenomena. I think it can, all terms properly defined.

This is an old question, which has come up again in a discussion that includes Russell Blackford, Jerry Coyne, John Pieret, and Massimo Pigliucci. (There is some actual discussion in between the name-calling.) Part of the impetus for the discussion is this new paper by Maarten Boudry, Stefaan Blancke, Johan Braeckman for Foundations of Science.

There are two issues standing in the way of a utopian ideal of universal agreement: what we mean by “supernatural,” and how science works. (Are you surprised?)

There is no one perfect definition of “supernatural,” but it’s at least worth trying to define it before passing judgment. Here’s Chris Schoen, commenting on Boudry et. al:

Nowhere do the authors of the paper define just what supernaturalism is supposed to mean. The word is commonly used to indicate that which is not subject to “natural” law, that which is intrinsically concealed from our view, which is not orderly and regular, or otherwise not amenable to observation and quantification.

Very sympathetic to the first sentence. But the second one makes matters worse rather than better. It’s a list of four things: a) not subject to natural law, b) intrinsically concealed from our view, c) not orderly and regular, and d) not amenable to observation and quantification. These are very different things, and it’s far from clear that the best starting point is to group them together. In particular, b) and d) point to the difficulty in observing the supernatural, while a) and c) point to its lawless character. These properties seem quite independent to me.

Rather that declare once and for all what the best definition of “supernatural” is, we can try to distinguish between at least three possibilities:

1. The silent: things that have absolutely no effect on anything that happens in the world.
2. The hidden: things that affect the world only indirectly, without being immediately observable themselves.
3. The lawless: things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law.

There may be some difficulty involved in figuring out which category something fits, but once we’ve done so it shouldn’t be so hard to agree on how to deal with it. If something is in the first category, having absolutely no effect on anything that happens in the world, I would suggest that the right strategy is simply to ignore it. Concepts like that are not scientifically meaningful. But they’re not really meaningful on any other level, either. To say that something has absolutely no effect on how the world works is an extremely strong characterization, one that removes the concept from the realm of interestingness. But there aren’t many such concepts. Say you believe in an omnipotent and perfect God, one whose perfection involves being timeless and not intervening in the world. Do you also think that there could be a universe exactly like ours, except that this God does not exist? If so, I can’t see any way in which the idea is meaningful. But if not, then your idea of God does affect the world — it allows it to exist. In that case, it’s really in the next category.

That would be things that affect the world, but only indirectly. This is where the dark matter comparison comes in, which I don’t think is especially helpful. Here’s Schoen again:

We presume that dark matter –if it exists–is lawful and not in the least bit capricious. In other words, it is–if it exists–a “natural” phenomena. But we can presently make absolutely no statements about it whatsoever, except through the effect it (putatively) has on ordinary matter. Whatever it is made of, and however it interacts with the rest of the material world is purely speculative, an untestable hypothesis (given our present knowledge). Our failure to confirm it with science is not unnerving.

I would have thought that this line of reasoning supports the contention that unobservable things do fall unproblematically within the purview of science, but Chris seems to be concluding the opposite, unless I’m misunderstanding. There’s no question that dark matter is part of science. It’s a hypothetical substance that obeys rules, from which we can make predictions that can be tested, and so on. Something doesn’t have to be directly observable to be part of science — it only has to have definite and testable implications for things that are observable. (Quarks are just the most obvious example.) Dark matter is unambiguously amenable to scientific investigation, and if some purportedly supernatural concept has similar implications for observations we do make, it would be subject to science just as well.

It’s the final category, things that don’t obey natural laws, where we really have to think carefully about how science works. Let’s imagine that there really were some sort of miraculous component to existence, some influence that directly affected the world we observe without being subject to rigid laws of behavior. How would science deal with that? …

Is Dark Matter Supernatural?Read More »

Craig Callender is a philosopher of science at UC San Diego, who has written a lot about the nature of time, including a fun illustrated book. He’s more than a bit skeptical of the multiverse idea, and somewhat contrarian about the low-entropy nature of the early universe: he thinks it’s just a fact we should observe and accept (“nomological”), rather than a feature that cries out for a better explanation.

Here we’re having a chat on the recently launched Philosophy TV, sort of Bloggingheads for philosophers. Craig’s head obviously looms much larger than mine, so I had to use my wiles to bob and weave, intellectually speaking.

Callender and Carroll from Philosophy TV on Vimeo.