Feser on Heisenberg on Act and Potency
In my view, the most important question in the ID-Darwinism debate is this: what do we mean by design? All participants in the debate agree that living things manifest design of some sort; Darwinists assert that the design is unintelligent, the product of ateleological genetic variation and natural selection. ID proponents assert that design implies an intelligent source. Philosophers of an Aristotelian and Thomist stripe assert that teleology pervades nature, but insist that a proper understanding of teleology entails a metaphysical understanding of nature (hylomorphism) that differs from the metaphysical presuppositions of most ID advocates, who generally accept (implicitly if not explicitly) the mechanical view of nature shared by materialists.
In my view, we need to integrate our understanding of the obvious design that is manifest in biology with the teleology that is evident in all of nature. We need a "unified theory" of teleology in nature that intrinsically explains the obvious design in living things as well as the obvious teleology in scientific "laws" and in all natural change. That integration necessarily will come from the "teleology" camp; Darwinist "ateleology" is an impoverished philosophical mistake that persists only when it not made explicit. The ID-Darwinism debate is rapidly eroding materialist credibility, not only because of the strength of the ID arguments, but because ID proponents have forced materialists to state clearly what they believe. Candor is incompatible with materialist ideology; Darwinists are angry in large part because they've been forced to explain themselves.
Can a teleological understanding of nature of an Aristotelian sort bring together the seemingly disparate strands of modern science? Philosopher Ed Feser suggests that a hylomorphic understanding of quantum mechanics, which intrinsically depends on a teleological view of nature, provides a coherent framework on which to understand some counterintuitive aspects of quantum mechanics. His source for this insight is Werner Heisenberg, a pioneer in the development of quantum theory.
Feser notes that, unlike many contemporary scientists like Richard Dawkins and Jerry Coyne, Heisenberg was philosophically literate, and he understood that classical philosophical notions are essential for an understanding of nature. Heisenberg saw that the "strangeness" of quantum mechanics was merely strange to the modern mind; classical Aristotelian notions such as act (the actual manifestation of a property) and potency (the potential, but not actual, manifestation of a property) anticipated many of the seemingly counterintuitive findings of quantum mechanics.
One might perhaps call [the statistical nature of quantum theory] an objective tendency or possibility, a "potentia" in the sense of Aristotelian philosophy. In fact, I believe that the language actually used by physicists when they speak about atomic events produces in their minds similar notions as the concept "potentia." So the physicists have gradually become accustomed to considering the electronic orbits, etc., not as reality but rather as a kind of "potentia." ...The probability wave of Bohr, Kramers, Slater... was a quantitative version of the old concept of "potentia" in Aristotelian philosophy. It introduced something standing in the middle between the idea of an event and the actual event, a strange kind of physical reality just in the middle between possibility and reality...The probability function combines objective and subjective elements. It contains statements about possibilities or better tendencies ("potentia" in Aristotelian philosophy), and these statements are completely objective, they do not depend on any observer; and it contains statements about our knowledge of the system, which of course are subjective in so far as they may be different for different observers...If we compare [the quantum mechanical relationship between matter and energy] with the Aristotelian concepts of matter and form, we can say that the matter of Aristotle, which is mere "potentia," should be compared to our concept of energy, which gets into "actuality" by means of the form, when the elementary particle is created.
Feser notes that Heisenberg's understanding of Aristote's notions of potency and act is not precisely correct in several ways, but he points out that Heisenberg understood that classical hylomorphic understanding of nature anticipated some of the "counterintuitive" aspects of quantum mechanics.
In any event, it is clear that what Heisenberg is defending is a core thesis of [Aristotelian-Thomist] philosophy of nature, namely that we cannot make sense of the physical world behaving as it does without attributing to its basic components inherent powers which point beyond themselves to certain (often as yet unrealized) ends -- a thesis that, as I have noted before, contemporary writers like Ellis, Cartwright, Molnar, and other "new essentialist" philosophers of science are starting to rediscover.
In my view, we are in the midst of a philosophical revolution. Like the materialist 'Mechanical Philosophy' revolution in the 18th century, the 20th and 21st century philosophical revolution is driven by contemporaneous advances in science. It began with quantum mechanics in the early 20th century, is now shaking the foundations of biology, and in time will cast aside simplistic materialist theories of the mind.
It is a corrective, really, to a banal philosophical mistake-- the assertion that nature was a 'machine', a system of passive matter organized by externally-imposed laws and comprehensible without reference to inherent essences and teleology. The strangeness of quantum mechanics has a simple explanation: 'mechanical system' is a woefully impoverished paradigm for nature. Nature is not a machine composed of passive parts acted on by external agency. Science is revealing that intrinsic essences and teleology pervade nature. Materialistic 'mechanism' as a philosophical system (if one can call a transparent mistake a 'system') leaves nature inherently incomprehensible. Materialistic Mechanical Philosophy is a philosophical system that creates philosophical problems; it doesn't, and can't, explain nature. Neither quantum mechanics, nor biology, nor the mind can be understood in the materialist paradigm.
Phillip Johnson is right: the debate about Darwinism is a philosophical debate. It is a debate about the metaphysical basis of science. This much about the denouement of the debate is clear: materialism and mechanism are dying. They are under siege from many fields of science-- from physics, from biology, from neuroscience. Its replacement is as of yet unclear, but an application of classical Aristotelian-Thomist philosophy to a 21st century understanding of nature (New Essentialism) is underway. It is a cogent and even elegant approach to understanding nature, and I believe that it has much to offer for our modern understanding of biology. It is quite compatible with 'evolution' understood as biological change over time and stripped of crude Darwinist metaphysics. New Essentialism may provide the insight into biological design that Darwinian materialism has utterly failed to provide.