Vertical uniformity of nature

One often talks of the “uniformity of nature” in the context of the problem of induction: the striking and prima facie puzzling fact that the laws of nature that hold in our local contexts also hold in non-local contexts.

That’s a “horizontal” uniformity of nature. But there is also a very interesting “vertical” uniformity of nature. This is a uniformity between the types of arrangements that occur at different levels like the microphysical, the chemical, the biological, the social, the geophysical and the astronomical. The uniformity is different from the horizontal one in that, as far as we know, there are no precisely formulable laws of nature that hold uniformly between levels. But there is still a less well defined uniformity whose sign is that same human methods of empirical investigation (“the scientific method”) work in all of them. Of course, these methods are modified: elegance plays a greater role in fundamental physics than in sociology, say. But they have something in common, if only that they are mere refinements of ordinary human common sense.

How much commonality is there? Maybe it’s like the commonality between novels. Novels come in different languages, cultural contexts and genres. They differ widely. But nonetheless to varying degrees we all have a capacity to get something out of all of them. And we can explain this vague commonality quite simply: all novels (that we know of) are produced by animals of the same species, participating to a significant degree in an interconnected culture.

Monotheism can provide an even more tightly-knit unity of cause that explains the vertical uniformity of nature—one entity caused all the levels. Polytheism can provide a looser unity of cause, much more like in the case of novels—perhaps different gods had different levels in nature delegated to them. Monotheism can do something similar, if need be, by positing angels to whom tasks are delegated, but I don’t know if there is a need. We know that one artist or author can produce a vast range of types of productions (think of a Michelangelo or an Asimov).

Any case, the kind of vague uniformity we get in the vertical dimension seems to fit well with agential explanations. It seems to me that a design argument for a metaphysical hypothesis like monotheism, polytheism or optimalism based on the vertical uniformity might not have some advantages over the more standard argument from the uniformity of the laws of nature. Or perhaps the two combined will provide the best argument.

The vertical harmony of nature?

One kind of harmony of nature is widely noted: laws of nature that hold at one place and time tend to hold everywhere else. This is a kind of horizontal harmony of nature.

But maybe there is also a vertical harmony of nature. Nature has multiple levels. There is the fundamental physics, the chemistry, the biology, the psychology and the sociology of the world; and also, along a parallel hierarchy starting with the chemistry of the world, the geology and astronomy of the world. The unity I am interested in between these levels is subtler: it is that essentially the same scientific methods yield truth at all these levels. Granted, there are modifications. But at all the levels, the same inductive techniques are used, and relatively simple mathematical models are made to fit reality.

Suppose that all the higher levels reduce to the fundamental physics. I think it is still surprising that the methods that work for the reducing level continue to work for the reduced level. And if there is no reduction, then the vertical unity is even more surprising.

There may be a teleological argument here. But I am worried about three flies in the ointment. The first is that perhaps I am exaggerating the unity of methods of investigation between the different levels. In school, we learn about "the scientific method". But in fact the methods of investigation in the different sciences are perhaps rather less similar than talk of "the scientific method" suggests.

The second is that the unity between the levels may simply be an artifact of the method. In other words, we have a certain method of mathematically and inductively modeling reality. And the levels that I am talking about are nothing but areas where the method works fairly well. And there is nothing that surprising that given an orderly fundamental level, among the infinitely many other "levels" (not all in a single hierarchy; just as above we had two separate hierarchies, one going up to sociology and another to astronomy) of description of reality, there will be some that can be modeled using the same methods, and those are the levels we give names like "chemistry" and "geology". In other words, we have a selection bias when we set out the case for vertical order.

If this worry is right, then we should only be surprised by the order we find at the fundamental level. But, my, how surprised we should be by that!

And, further, if we see things in this way, we will see no reason to privilege scientific approaches epistemologically. For there is nothing that special about the sciences. There may be infinitely many levels of description of reality which can be better known using other methods.

The final fly in the ointment is that while there are a number of levels that can be known using the same methods, there seem to be areas where we have genuine knowledge, but the scientific methods do not work: ethics is a particularly important case.

So in the end, I do not know really what to make of the vertical harmony thesis. It bears more thought, I guess.

More on science and theism

One of the puzzles in the scientific explanation literature is how it is that one can genuinely have explanation in the special sciences—chemistry, biology, geology, etc.—given that the facts in the purview of the special science in question appear to reduce to facts of physics, and hence it seems that only physics-based explanations are appropriate. One strategy is to resist the reduction move. I am happy to resist the reduction move for biology, but to me reduction seems exactly right for geology and probably for chemistry.

The theist, however, has a neat story, like the one in my previous two posts. The patterns that the special science identifies are valuable. They are valuable intrinsically—they exhibit an aesthetic good (and scientists talk of the beauty of theories, though admittedly they do so less in the special sciences)—and they are valuable instrumentally as they make it possible for us to make predictions and organize our knowledge. Because these patterns are valuable, God intends them and their presence is causally explicable. This holds whether or not the given generalization in the special sciences rises to the level of laws or not.

What happens, though, when one pattern is subsumed into a wider pattern? As long as the narrower pattern is still there, it can be correctly used for explanation. But explanation in terms of the wider pattern is better, because the wider pattern is more valuable, and hence more explanatory of God's creative action. Thus, early on we may have learned that all mammals have hearts, and later on we learned that this is true of all vertebrates. It is still correct to explain the presence of the heart in Socrates by his mammality, but better to do so by reference to his being a vertebrate.

A similar move explains why it is that when there are two formulae that equally fit all the data, the simpler is the one to be preferred in explanation. This is relevant to both the curve-fitting problem and the problem of which of two mathematically equivalent formulations is the more explanatory.

Furthermore, that some simple theory approximately fits a body of phenomena is also of value. Hence, theories that are mere approximations can yield genuine explanations. And that is how it should be. In particular, Newtonian mechanics continues to be explanatory, and not simply because of classical-limit stuff in quantum mechanics.

The theistic story also explains why it is that Lagrangian mechanics was genuinely explanatory, despite not fitting well in the mechanistic model of explanation. This is, of course, an application of Leibniz's discussion of teleological explanation.