This is a complex question, because there are many different assertions made by Intelligent Design theorists. Most of those assertions amount to attacks on Evolution Theory (which I address back on Empirical Doubts.) But one cannot prove an assertion by disproving a competing assertion, unless the two assertions exhaust all of the possibilities. Surely Evolution Theory and Intelligent Design do not exhaust all of the possibilities, so any argument which purports to show that Intelligent Design is right by showing that Evolution Theory is wrong is fallacious. The fallacy, known as False Dilemma, should be evident from the following example:
It know that you don't hate me, therefore you must love me.
But love and hate do not exhaust all the possibilities --- perhaps you only like me, or you are indifferent toward me.
So what positive assertions are made in Intelligent Design? The one positive assertion is that, given empirical evidence consisting in the complexity and complex adaptation of what we see, what we see must be the result of intelligent design. Now the fact that the argument invokes empirical evidence does not mean that it is scientific by that reason alone. There are many possible arguments which are based on empirical evidence, which I would not call scientific. For instance,
Based on the fact that all of the 9/11 highjackers were of Arab descent, I conclude that all Arabs are terrorists.
The fact that all of the 9/11 highjackers were of Arab descent, although it is empirical evidence, is insufficient to justify the conclusion that everyone of Arab descent is a terrorist.
Thus the question becomes, does the empirical evidence alone support the conclusion? To see why it does not, let us look more closely at the conclusion. Inherent in it are two assumptions that I think make Intelligent Design unscientific (although not necessarily false), and unsupportable from the empirical evidence we have on hand. First, the conclusion assumes that we can recognize design from empirical evidence. It is not at all clear that this is possible: recognition of design involves identifying to some extent the goals and abilities of the designer; but natural science is not really in the business of characterizing goals and purposes, and empirical evidence can be equivocal when it comes to deciding between goals and purposes. Now to be honest, this objection does not carry too much force if we stay in the world of human goals and abilities, because we have lots of experience in that world. Thus it is easy for us to recognize human design. But although Intelligent Design theorists do not specifically invoke God as the intelligent designer, but they do not exclude that possibility either. Can there be any good empirical evidence about the goals and abilities of a possibly supernatural being? (This is the basis of Elliott Sober's (2002a) critique of the Intelligent Design --- more on that to come.)
And this brings me to the second assumption that I think makes the argument unscientific. If we grant the conclusion, then we grant at least the possibility that what we see is to be explained by invoking the supernatural. Since science is in the business of getting a handle on natural processes, the conclusion of the Intelligent Design argument amounts to an assertion outside the realm of science. Supernatural intervention, when viewed scientifically, is not so much an explanation as the lack of one, since science limits itself to naturalistic explanation.
To explain, if a scientist detects a phenomenon which falls outside of natural law as we now know it, further experimentation is performed in order to figure out how our versions of natural law can be modified to more accurately reflect and predict what happened. Think of the failure of Classical Mechanics to accurately predict what happens in the realm of the very fast and in the realm of the very small --- new mechanics were formulated and successfully tested in both cases: Quantum Mechanics and Relativity. To ascribe what happened to the supernatural --- a violation of natural law --- is a non-starter for science; it is unscientific. (This conclusion applies whether one thinks that natural law exists independently of our knowledge of it, or one thinks that science formulates its notion of natural laws merely to better predict phenomena.)
Another point that bears mentioning is that it is hard to imagine a series of experiments that help to confirm Intelligent Design. What kind of apparatus would be required to demonstrate the mechanism it posits, that of intelligent design by a possibly supernatural being? (Read on through the attacks on Evolution Theory and you will see that each of its mechanisms has been experimentally reproduced by scientists.)
Thus Intelligent Design should not be described as scientific, should not be taught as science, and should not find its way into science textbooks adopted by the public school system. Now I am not arguing that belief in supernatural entities is antiscientific or that science is necessarily anti-religious; what I am arguing is that supernatural entities do not enter into scientific descriptions, models, and theories.
Of course, there is no reason not to consider the positive assertion of Intelligent Design as a philosophical assertion rather than a scientific one. This is, in fact, how I will treat it from here on out.
Please return to Empirical Doubts.
