We tend to think of reality as made up of things, governed by fixed laws that determine how they change over time. But biochemist Timothy Jackson argues that this is back to front: fundamental reality is a lawless flux, a chaos of unpredictable change, and what needs explaining is not chaos but the stability and order that emerge from it. The “laws” of physics are not eternal truths but descriptions of patterns that have persisted long enough to look permanent. Darwin’s central insight, Jackson suggests, was to show how such order might emerge, via natural selection—a principle which can explain, but never predict, the patterns that make up the world.
From physicalism to “biologism”
From panpsychism to “Platonic Space,” assertions that we need to move “beyond physics” are increasingly common among scientists and philosophers. Whilst it’s nothing new for different sciences to be associated with distinct worldviews, current conversations seem to be more explicitly metaphysical than has traditionally been the case among scientists. It seems that the disavowal of metaphysics as a meaningful pursuit hasn’t really expunged it from modern science, so much as hidden it. The common-parlance term for the dominant—and largely tacit—metaphysics of modern science is “physicalism,” and it is this that so many are arguing we need to move beyond.
I’m a biologist, working on molecular evolution and chemical ecology—the ways in which organisms mediate their relationships with one another using bioactive molecules—so it may be unsurprising if I agree that a metaphysical paradigm which seems to match the intuitions of physicists isn’t “enough.” Like many biologists, I use physics-derived models to help me understand the systems I study. However, a key difference between physics and biology—at least methodologically—concerns the relative status of variation and invariance. Physics tends to operate via a search for invariant principles or “laws” that govern the behavior of variables. Invariant parameters are embedded in physical models in ways that generate a predefined “state space,” which corresponds to the possible trajectories of the basic elements the theory applies to. These invariants can also be understood as the theory’s basis of reduction or principle of “coarse-graining”—all meaningful variation is understandable in terms of this reduction base and the rest is noise.
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Molecular biology and the “Neo-Darwinian” paradigm have become notorious for attempting to mould biology in the image of physics.
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The situation in biology, as I see it, is almost the opposite. Indeed, Charles Darwin’s major insight was to see that in biology, everything varies. All of an organism’s character states are potentially plastic—this variation is “random” in the sense that it is intrinsically unpredictable by recourse to any dimension of reduction, i.e., any model, theory, or “law.” Darwin realized that, given the extent of the variation exhibited by the character states of the organisms he painstakingly observed, some principle was required to explain why that variation was, nonetheless, not completely continuous, but exhibits evident order. You cannot start by defining invariant properties, or you’ll just end up with a never-ending string of exceptions that seem increasingly unlikely to prove the rule. But variation is patterned, clumpy—where one taxonomist and the next draw the boundary between two species might be somewhat arbitrary, but it’s nonetheless the case that there are two distinct populations being observed. Enter the principle of selection (“natural” or otherwise) as a way of explaining why some variants proliferate and others do not, and why those that proliferate end up forming moderately stable groupings.