Editor’s note: The new book Nature’s Prophet: Alfred Russel Wallace and His Evolution from Natural Selection to Natural Theology is officially out today! Nature’s Prophet is currently on sale here for $26, a substantial saving from the list price of $44.95.
Wallace was the co-discoverer with Charles Darwin of the theory of evolution by natural selection. He later broke with Darwin over the question of teleology. We asked the author, science historian Michael Flannery, to define the difference between intelligent design and Wallace’s case for what Professor Flannery calls “intelligent evolution.”
Intelligent design (ID) is the theory “that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.” Stephen Meyer, in Signature in the Cell, explains that ID “holds that there are tell-tale features of living systems and the universe that are best explained by an intelligent cause — that is, by the conscious choice of a rational agent — rather than an undirected process.”
Intelligent evolution (hereafter IE), as I describe it in Nature’s Prophet, is “a theory of common descent based on natural selection strictly bounded by the principle of utility (that is, the idea that no organ, attribute, or morphological feature of an organism will be developed and retained unless it affords it a survival advantage) within a larger teleological and theistic context.” In other words, as understood by Alfred Russel Wallace, IE is directed, detectably designed, and purposeful common descent.
Distinctive and Common Features
Placing these terms alongside one another immediately reveals their distinctive and common features. First, ID by definition makes no mention of common descent or evolution per se, only that nature gives evidence of purposeful intentionality. It takes no position on common descent, the tree of life, or really how diversity on this planet came into being and developed; it only states that however the change through time occurred it did so by some means other than a blind, undirected process. Second, it has no religious or theistic commitment, nor does it even suggest what agency is behind this purposeful intentionality.
God as described in the Abrahamic religions, some telic principle, process philosophy, or some version of Neoplatonism are all available but not exhaustive options. Thus, ID is an extremely broad and general term. The one thing essential to it is directed and intelligent causation. As such it is inherently teleological. This being the case, it can readily be seen that IE is a more specific term that describes how evolution operates. It is committed to common descent and even to natural selection, but regards both as insufficient in themselves to explain life and its diverse complexity. Therefore, the tie that binds ID and IE together is their rejection of chance and necessity as meaningful explanations for nature at the cosmological and planetary levels.
A Veritable Thesis Statement
Is it fair, then, to regard ID as synonymous with IE? Bearing in mind the distinctions given above, I would argue that they are thoroughly harmonious if not completely synonymous. A moment’s reflection will see why. None of the commitments made by intelligent evolution concerning common descent or natural selection are ruled out of court by ID; the latter is silent on them. Think of Wallace’s own book, The World of Life: A Manifestation of Creative Power, Directive Mind and Ultimate Purpose. It’s hard to imagine any clearer affirmation of intelligent design than that; the subtitle stands as a veritable thesis statement for ID.
Again, IE is more specific than ID, so some within the ID movement would not consider themselves its proponents. However, others would. The dividing line for ID is not common descent, or theism; the dividing line is chance versus direction, blindness versus guidance, largely stochastic processes versus specified complexity. Evolution by means of common descent but imbued with intelligence is fully consonant with ID. John West has explained this with great clarity.
The Wallacean Model
If any modern ID proponent fits the Wallacean model it is biologist Michael Behe. Of course Wallace knew nothing of genetics or molecular biology, but he, like Behe, could readily see the machinery of life embodied in the intricate systems of the cell and certain biological forms. Furthermore, Wallace pointed out to Darwin that “Natural selection…does not so much select special variations as exterminate the most unfavourable ones.” Elsewhere he said, “The survival of the fittest is really the extinction of the unfit.” The inability of natural selection to create but only to cull has been recently updated by Behe in his suggestion that loss-of-function mutations form the “first rule” of adaptive evolution. More generally, Behe writes:
The idea of intelligent design, although congenial to some religious views of the universe, is independent of them. For example, the possibility of intelligent design is quite compatible with common descent, which some religious people disdain. What’s more, although some religious thinkers envision active, continuing intervention in nature, intelligent design is quite compatible with the view that the universe operates by unbroken laws, with the design of life perhaps packed into this initial set-up. In fact, possibilities two and three listed above — where non-randomness was assigned either to complex laws or to the environment — can be viewed as particular examples of this. I think it makes for greater clarity of discussion, however, just to acknowledge explicitly in those cases that the laws or special conditions were purposely designed to produce life.
(Michael Behe, The Edge of Evolution, p. 166)
Alfred Russel Wallace would not have disagreed, and indeed argued in much the same way. Both he and Behe searched for the limits of Darwinism and found them in intelligent evolution.
Photo credit: “Beetles collected in the Malay Archipelago by Alfred Russel Wallace” (cropped), ©Natural History Museum, London, via Flickr.