Afterthoughts: Teleology and the anthropic principle

First, an apology: I've written before on the anthropic principle (AP), but the AP is used in widely varying senses, and my earlier postings didn't meet this issue directly. Nowadays, you see the AP popping up in two very different ways in two very different contexts - in the evolution/intelligent design controversy and in string theory. I've mainly posted about the latter case, but the former is better-known and more interesting.

There is a sense of the AP (the strong form) which implies teleology or final (purposive) causation. Stated in modern language, teleology or purposive causality is a generalization of the intentionality inherent in living and especially consciousness entities. It need not involve human-like consciousness. The key difference between final causation and reductionism is that reductionism posits a fundamental causality that is purely past-conditioned and purely forward-looking; it contains no feedback. Purposive causality requires "feedback loops" and implies some kind of circularity in the causal sequence. That living and conscious entities exhibit such circular feedback in their purposive behavior is not in dispute; the question is whether such causality is secondary, or if non-living entities and possibly the universe as a whole exhibit such feedback. If the latter, then teleology is fundamental to the universe; if not, it is a secondary phenomenon piggy-backing on a fundamentally causal but "blind" non-purposive universe.

A popular example of teleological reasoning is the "argument from design" or Intelligent Design (ID). But the AP is simpler and more general than that, and it doesn't have to be supernatural or theistic. The classic example in Western philosophy is Aristotle's four-fold causality (first, material or efficient, formal, and final); his system is neither theistic nor supernatural. Modern science started in the 17th century, attended by a philosophical revolution brought off by Descartes, Spinoza, and Locke. The agnostic or negative position of these early modern thinkers on final causality was crucial in the birth of modern scientific thinking. Spinoza's position was the most radical and consistent: he believed in a universe with design but without purpose. His militant monism (one Substance with many Modes) and unqualified belief in blind determinism have the appeal of consistency, but beg the question: purposive causality is inescapable for understanding living entities, and even more so, conscious ones. Descartes' solution was an extreme dualism: human consciousness (res cogitans = thinking stuff) is a supernatural soul; everything else (including our bodies and other animals) is a blind machine (res extensa = matter-energy in spacetime). Unfortunately, this solution, still very much with us as a pratical rule of thumb, has gradually been knocked down by modern biology, psychology, and medicine. Aristotle's unified treatment of all forms of biological teleology is theoretically superior. At the end of the 17th century, Locke had what, for modern science, has amounted to the final word on this question, which has seen no real improvement since. Agnostic on the role of teleology in the universe at large, Locke admitted that final causes are inescapable for understanding any kind of life. However, Locke also believed that "G-d could make matter think" and held out the hope that Descartes' dualism could ultimately be overcome. Hume in the 18th century attacked intelligent design and purposive causality, but from a quite different direction, casting doubt on causality and objective knowledge altogether. Such skepticism leads, not to modern science, but in a nihilistic direction first explored by Nietzsche in the late 19th century; it needn't detain us here.

What's the bottom line? The rejection or suspicious treatment of final causes is not a result of modern science, but an assumption. Modern science has made far more progress on "what" and "how" questions than on "why?". That fact alone justifies this approach, but it leaves unanswered the "why" questions that everyone ever born has thought of. The status of final causality remains elusive: is it a fundamental metaphysical category or a secondary of non-purposive causality?

This type of AP makes no sense in a Newtonian world, which is just such a world of blind determinism, driven by causal laws and conditioned only by past events. In modern physics, with quantum mechanics, non-equilibrium thermodynamics, and modern cosmology, such questions can be asked again, but we still lack definitive answers. Obviously, a teleology acceptable today would be very different from Aristotle's, since our knowledge of physical and biological mechanisms is broader and deeper than his was. It would be more abstract and simpler, and would hinge essentially on information or entropy, treated as a co-equal to spacetime and matter-energy. Information is inherently selective; it selects some of the world as "signal" and rejects the rest as "noise." Such selectivity is visible everywhere in the living world, from nutrition and waste elimination (eat this, flush that), to consciousness (attention to this, ignoring of that), to evolution by selectional mechanisms (this fits, that doesn't).

Philosopher Thomas Nagel recently penned a penetrating treatment of final causation in the form of a review of Richard Dawkins' new book, The God Delusion (requires subscription). By way of talking about Darwinist-selectional theories of biological evolution, Nagel takes Dawkins and others to task for overstating their case: Darwin's theory explains the origin of species, but not the origin of life - it doesn't and can't answer such a question. (Amusingly, Dawkins has to fall back on the hand-waving of the weak AP, invoking billions and billions of planets, instead of billions and billions of universes - explaining nothing - see below.) And Darwin's theory is a non-teleological (although not deterministic) theory - all modern scientific theories are: by assumption, not because they prove final causes invalid.

Since the 17th century, purposive causality has lived in a limbo of "parascience"; if it involves super- or "extra"-naturalism, it falls outside science altogether. The best-known case in recent years is the ID movement, which is attempting to re-introduce strong teleology into biology, a purposive causality set up by a human-like designer. In practice, many invocations of final causes are scientifically redundant, unfalsifiable, or empty. That fact is the (generally sound) basis for attacking the ID movement as pseudo-science. And many attempts to import ID theory into biology teaching are much cruder than that, just thinly veiled forms of creation "science," an obvious anti-science, as it rejects not just Darwinian selectional theories, but the whole framework of modern cosmology, geology, biochemistry, and genetics.

But in a final irony, the "other" AP controversy raging right now - about the weak form of anthropic reasoning invoked by string theorists - shows the AP in a much worse and far more objectionable light than the ID controversy. This non-teleological form of the AP proposes an infinity of unobservable universes, with no method to enumerate them, and offers no explanatory power whatever. It gives up on the project of modern science, seeking unity among observable phenomena: matter and energy, space and time, living species as descended from a common ancestor and sharing the same biochemistry, etc. The weak AP is a flight from scientific reason, driven by blind clinging to string theory. That theory isn't a real theory anyway, only an unlikely conjecture, and its solutions are more conjecture. As astrophysicists devise thought-universes with slightly different physical laws that can also support life as we know it, the reasoning behind this form of the AP falls apart. Its sole appeal is to people who believe in string theory for other reasons anyway (and bad reasons at that). This weak, multiverse AP is truly "millennial madness." It widens the already large chasm between string theorists and the rest of science and pushes string theory even further down the road of becoming a self-validating cult. And it makes creationism and ID look good by comparison - almost like real science.