review of Scott Turner's "Purpose and Desire"

I heard a talk by Scott Turner through Heterodox Academy that pointed me to his book, Purpose and Desire. (I can’t find the podcast now, but it was really good: two guys who asked him questions and were worried/skeptical about the implications of his work. Here’s Turner’s website.) After hearing Turner interviewed, I bought a copy and read it. (I had already heard about the book somewhere, bought a copy, and stuck it on one of my bookshelves at school. I just ran across it the other day!)

The explanation for the title doesn’t come until the end—as a “counterfoil” to Jacques Monod’s Chance and Necessity—a “luminous, influential… beautiful, deep” book, the thesis of which “rests upon what I have come to believe is a distorted picture of the history and philosophy of the science of life.” (300)

The problem? In the early-20^th century, “biology sold its soul, so to speak, committing the practitioners of the science of life wholesale to the essentially philosophical premises of mechanism and materialism.” (xi) It seemed sensible at the time—and an opportunity to be viewed as a harder/real science (what he calls “physics envy” [47]). It has also yielded valuable insights into science and its applications. But how broadly is it true?

This is a common and generally fruitful approach within science: simplifying the world through models and statistics, as we try to understand a simplified (but not simplistic) version of an immensely complex reality. The questions are always whether the stats and models are good simplifications, the extent to which the inferences derived from those simplifications are accurate, and so on.

But one should always remember that the models are simplifications, not the reality themselves—and that models always fall short, sometimes in vital ways. Sadly, this is often overlooked. Along these lines, Turner describes himself as a “recovering reductionist.” (301) And it’s this sort of reductionism (whether literalism, fundamentalism, or an overly-fervent adherence to other isms) that often causes so much blindness, dogmatism, pride, and error.

One part of Turner’s thesis (and the subtitle of the book) is that science has failed in this regard—with respect to what constitutes “life”. His opening example is to ask whether a cauliflower and a cumulus cloud are “alive”—and why. What seems obvious (cauliflower: yes/maybe; cloud: no) is not all that clear when one digs deeper and tries to use coherent definitions. When he teases it out, “there are really distinctions only in order and not in kind.” (xiii) Cauliflowers have genes and “hereditary memory”, but clouds have a type of this as well—defined as “some means of shaping the future as a reflection of the past.” (xiii)

In a word, “we don’t have a good Darwinian explanation for the origin of life. Part of the reason for this is that we don’t have a good Darwinian explanation for what life is in the first place. Nor do we have a good explanation for the origin and evolution of the cornerstone of the edifice of modern Darwinism, the gene. If that weren’t enough, Darwinism is also have a rather hard time explaining what an organism is…The problem for modern Darwinism is, I argue, that we lack a coherent theory of the core Darwinian concept of adaptation.” (7)

Turner looks at all of this differently as a physiologist (the study of “how living things work” [12]), rather than a biologist (“the study of life”). Along the way, Turner provides brief biographical sketches of key players in the history of physiology—most notably, Claude Bernard. And in one of his presentations, he provides a wonderful diagram on the philosophical priors that each field finds attractive. (I have pasted it at the bottom.)

In particular, he is provoked by a vital concept in physiology: homeostasis—the body’s “steady state”. Is life a machine? Yes and no. “Yet striving and desire seem to occupy a lot of what life does.” (13) If so, it’s not just the how but the why that is important to consider and explore (14-15). A big question/distinction is whether the “intentionality” we all perceive is real or only apparent. If it’s real, a scientist can ignore it for a time (see above on models), but can’t ultimately ignore it—or certainly, dismiss it (viii-xi).

Turner uses the adaptation of lizards to the temperature of their environment as an example (68ff). And apparently there is some economics involved in the standard analysis: as the costs of adaptation increase, lizards will make fewer efforts to adapt. For example, if the likelihood of predators is higher, they will instead tolerate the costs of not adapting to the environment so much. Turner is quick to say this is not “thinking” but “intentionality” and homeostasis: “the reshaping of the real world…involves a kind of wanting, an actual desire to attain a particular state, and the ability to create that state.” (70)

Chapter 5 is good on “the rise of Darwinism” and the good it wrought (vs. the goods that were being achieved previously). He describes the contributions of Linnaeus, Lamarck, and Cuvier. (Other key players later: Weismann and Cope in chapter 6; Morgan, Driesch/Roux, and Fisher/Wright/Haldane in chapter 7.) He also details the efforts of Darwin on “pangenesis” (hypothesized through “gemmules” and published nine years after Origin of Species). And then a broader point (97): the tension between adaptation (the ability to change) and hereditary (“the opposite of change, that is, the legacy of the past imposing itself on the future”).

Turner turns to Margulis in chapter 8 in his discussion of “hereditary memory”, the metabolism and symbiosis of LECA (the “last eukaryotic common ancestor”), and the competing explanations for this (178-180). The options are natural selection as a tautology or using intentionality and cognition in their broadest senses. He provides his best example of the tautology later: “Why are there flying animals? The trivial answer is because animals have evolved to fly.” (284)

In chapter 9, Turner wrestles with “organism” vs. “individual”—with interesting examples: a swarm of bacteria, symbiotic organisms (e.g., lichen), and organisms on organisms (“my body is populated by ten times as many alien cells—bacteria, yeasts, and fungi—as ‘my’ own cells” [189]). “Quite a lot is at stake in this question, because an implied individuality sits at the heart of the Darwinian idea. It is individuals that compete with one another.” (190)

From there, he describes “the Hamilton rule” (198) to deal with altruism among social insects—except that it runs into big trouble with termites. (Much of Turner’s research has focused on termite communities. He has been impressed by their ability as a group despite their ineptitude as individuals—e.g., to repair damage to a colony.)

Chapter 10 is devoted to science’s inability to explain the origins of life. The “prebiotic chemistry” soup plus energy story requires that one “verge uncomfortably into miraculous thinking” (231). He discusses the famous Miller-Urey experiment which was successful. Of course, such success also—or only—points to “intelligent design”.

“Unfortunately, among the awful lot of things we have learned is how flimsy a foundation prebiotic chemistry is for building a theory of life’s origins. Worse, the more we have learned, the more daunting the problems have become.” (232) Some of the outstanding issues (232-234, 248): “yield” (what’s needed vs. the diverse stew that emerges from the experiments), “process” (a certain sequence with required environmental conditions), the “wild life” problem (as life arises in a lab vs. the real world), and “diffusion” (the things required to start life are routinely scattered as they come into existence).  

Scientists have their own “creation stories”—either through genes (what he calls “genism”) or through metabolism (what he calls “physism”). Turner says there’s no room for fundamentalism on this question: “Life has two attributes that demand explanation…the ability to store, transmit and implement hereditary memory; and the sustaining, order-producing phenomenon that is homeostasis…[At present], these two attributes are so tortuously intertwined that it is near impossible to imagine how one could have emerged spontaneously without the other being there first.” (229)

This takes Turner to “irreducible complexity”. (Turner notes that “the phrase has come to be fraught because of its use in ID theory [as made popular by Michael Behe]…[but] the phrase is nonetheless apt.”) To avoid ID, proponents “do so by blurring the distinction between heredity and metabolism” (235). In his chapter on the underlying philosophy of such things, he describes ID theory as “a rather harmless and benign resurgence of Neoplatonism” and its opponents as illiberal opponents of “academic freedom” (262) who have engaged in “shabby treatment” of “sympathizers” of ID theory (296).

Hopefully, Turner’s book will provoke thought among the blinkered and intellectually curious—and provide solace for free thinkers. Science is a wonderful thing when it’s practiced as Science rather than as counterfeit cousins based on flawed philosophical assumptions.