On one side are the "ultra-Darwinists," a term used by Stephen Jay Gould to criticize the stridency and excessive reductionism among some evolutionary biologists. On the other side are "creationists," who argue--against not only science but also those faiths that accept the compatibility of evolutionary biology and Sacred Writ--that the earth was created on or around Sunday, October 23, 4004 B.C., a conclusion based on a sincere but discredited calculation by James Ussher in the seventeenth century. At first glance, Intelligent Design seems to offer hope: While eschewing the Young Earth theory of creationism, it acknowledges the need, deeply embedded in scientists and theologians alike, to recognize final cause, or telos, in the created universe. At first glance, "ID" might sound reasonable, even the answer to our prayers. It is not.
The first set of criticisms of Intelligent Design comes from the scientific perspective. These are well known and have been written about elsewhere, at length. Readers interested in these arguments are urged to visit websites such as The Panda's Thumb. In brief: Such websites point to logical and factual flaws in the writings of the Intelligent Design movement and take issue as well with their intellectual honesty--as when, ever eager to write the obituary for Darwinian theory, they fail to acknowledge progress in evolutionary biology.
But my task is elsewhere: to take to task the philosophy and theology behind Intelligent Design.
I turn, first, to philosophical criticisms of Intelligent Design. The movement attributes large changes in biological history to an "intelligence"--but what, exactly, they mean by this term is left largely in abeyance. Most, though not all, members of the movement are Christians and, more particularly, Evangelical Protestants. That's as may be.
Perhaps to appeal to a broader base, they allow that this "intelligence" could be something other than God (an angel or extraterrestrial being, for example). But its being anything other than God would immediately raise the question of how such a being had arisen. Since they deny that even less advanced creatures, like trilobites, can arise by purely natural means, this is a big problem. So whether they arrive at it now or later, the conclusion seems unavoidable: Though reluctant to use the word, they are talking about the God of monotheism, and mainly the God of Christianity.
If God is omnipotent--that is, can do all that is possible without self-contradiction--what is the relationship between God and causality? Is there any causality outside an omnipotent God? Or is anything in nature that seems to act as an efficient cause only carrying out the causality of God, with no agency of its own? These questions get to the heart of a philosophical problem posed by Intelligent Design: It supposes that natural law, which is the basis for science, operates most of the time but is periodically suspended, as in the Cambrian "explosion" and the origin of life itself.
The philosophical belief that created substances cannot themselves be efficient causes is called "occasionalism." In Islamic thought, occasionalism is most closely associated with al-Ghazali in the eleventh century and al-Razi in the twelfth. The early-eighteenth-century philosopher Nicolas Malebranche is the Christian most associated with occasionalism.
Occasionalists vary in their view of natural (or physical) law. Some argue that God's rationality makes events occur in predictable sequences, giving the appearance of efficient causality in nature. Other accounts stress the inscrutability of God. They all, however, deny that efficient causality occurs outside God, and argue that there is no necessary, natural causal connection between two events seen in temporal and spatial conjunction. Instead, God causes first one and then another event. As Malebranche put it, God usually acts through "general volitions"--what we usually call natural or physical law--and rarely through "particular volitions" (miracles).
The Intelligent Design movement has not used the term "occasionalist" to describe itself, to my knowledge, but it is an occasionalist philosophy nonetheless. It does not credit natural or physical law with enough causal power to enact evolution on its own and educes supernatural causes to do most of the heavy lifting in worldly events. Fairly typical is this quote from Stephen Meyer's Darwin's Doubt: "Though many biologists now acknowledge serious deficiencies in current strictly materialistic theories of evolution, they resist considering alternatives that involve intelligent guidance, direction, or design."
The giveaway is the word "alternatives." He might have written about adding or harmonizing a religious view to a scientific one, but instead he wrote about "alternatives." (There are also serious questions about what he means by "strictly materialistic theories," but let that pass.) Thus Meyer argues that if one searches for the causes of the Cambrian explosion or the origin of life solely within the ordinary bounds of biology (a part of natural philosophy), one will look forever in vain, for these things...