When we design something, we typically make use of prior knowledge and techniques, and of the materials we have used or which hold promise for us on that basis. So, when we explain ordinary design we do this by packing a lot of information into the general model of design processes.
If I explain why Rosemary has uprooted a garden bed and replanted it with native plants, even though hitherto they had always planted English roses, and had given no indication of why she had done this or that she was about to, my explanation taps into a large body of default and even tacit knowledge of gardening practices, all of which is summed up in the general premise "Gardeners design gardens" or something similar.
I do not need to have a fully elaborated model of what either Rosemary is likely to do - that is, I don't need a complete or sophisticated model of Rosemary's predispositions to behave - nor do I need to explain why Gardeners occasionally uproot English roses to plant Australian native plants. My explanation is sufficient, so far as it goes, if I note a general tendency of Australian gardeners to plant Australian native plants, so long as it is understood that there are in fact reasons for this (they are more drought-tolerant, require less weeding, and are in fashion because people are coming to appreciate the esthetics of the Australian flora).
Such a general set of implicit rules makes the outcome "Rosemary replanted her garden with Australian natives" explicable, and indeed, more likely. Moreover, the explanation taps into that tacit knowledge base to assert something about Rosemary - that she is affected by that general set of considerations. To assert that Rosemary's Garden is the product of design is to assert something about her community, culture and the traditions of gardening.
Now if Rosemary attacked her garden with a hoe, leaving it in a state we would call disarray, we can only know that this is, in fact, disarray in contrast to some kind of Garden-dadaism or Floral Cubism, by making reference to the traditions of design and the expected variations that would count as acceptably Gardening. Maybe Rosemary just had a bad day, or a fight with her Significant Other.
Explanations fall in what Alan Garfinkel once called a "contrast space" set up by the variables of the question the explanation seeks to address. "Is Rosemary's Garden designed?" specifies a set of alternatives, and these together make a space of possible "yes/no" answers. Garfinkel illustrated this with the famous question asked of bank robber Willy Sutton: a priest asked him why he robbed banks. Sutton answered, "That's where the money is".
The priest was expecting a moral answer - Sutton robs banks because he needs the money or because he can't get a job. But Sutton has no moral issue here; it's purely a matter of practicalities. He robs banks rather than, say, druggists, because there's more money there. Sutton has a different contrast space than the priest. Explanations are relative to the contrast space required.When I explain that Rosemary's Garden is the product of design, there's a whole set of contrasts I am relying upon.
But the way the Intelligent Design crowd employ both the notions of "design" (to be a rarified rather than an ordinary notion),
and the notion of "explanation", there is no actual contrast space here - all is fluid. All that matters for them is "saving the theology", not "saving the phenomena". So long as something
like a God can be made to seem sensible, all is done that need be done. This is not science, and it's not even compatible with science. It is, and remains, epistemological despair, epistemic nihilism, Knownothingness.
Contrast that with the traditional natural theology that preceded Darwin. It had an honest intent - to uncover the nature of the Deity from the nature of his works. Or contrast it with the reaction to evolution of English Catholicism. The leader of the Oxford Movement, Cardinal John Henry Newman noted that evolutionary biology was not opposed to God or creation, and wrote:
I have not insisted on the argument from design, because I am writing for the 19th century, by which, as represented by its philosophers, design is not admitted as proved. And to tell the truth, though I should not wish to preach on the subject, for 40 years I have been unable to see the logical force of the argument myself. I believe in design because I believe in God, not in a God because I believe in design.
[Quoted in Ruse 2003, 72. This is a good, if simplified, introduction to the role design has played in Christian thought in the English speaking world, though I should like to have seem more of John Ray, the founder of natural theology, and of those who followed him in the 18th century.]
In Germany though, Catholics were less sanguine about evolution due to the aggressive evangelical materialism of Ernst Haeckel. Still, nobody thought that design proved God, or protected theism from science. Newman was happy for science to continue without reference to God. He saw that in science the contrast space of explanations did not include final causes, except, as Francis Bacon noted long ago, with reference to human behavior:
It is a correct position that "true knowledge is knowledge by causes." And causes again are not improperly distributed into four kinds: the material, the formal, the efficient, and the final. But of these the final cause rather corrupts than advances the sciences, except such as have to do with humanaction.
[Francis Bacon, Novum Organon, aphorism 3]
Bacon knew that to assert that design, or teleology, applies to the natural world is a case of what Freud came to call
projection - asserting that something natural is like human choice. I will thus finish here with a quotation from the leading critic of design talk in biology, Susan Oyama:
Powerful and protean and far from being banished from secular science, the argument from design is ubiquitous. Perhaps because we are creatures whose existence and survival depend on our ability to discern regularities in our surroundings and in turn leave our mark, our design, on them, we tend to infer prior design or intent from observed regularity. We formulate, that is, a descriptive rule, which is a form of knowledge, and infer from it a prescriptive rule, which is separate from the processes we see and controls them.
That's enough about design. It's really rather boring. Next, I will do a series on classification if I can find the time and mental acuity.
Garfinkel, Alan. 1981. Forms of explanation: rethinking the questions in social theory. New Haven, Conn: Yale University Press.
Oyama, Susan. 1985. The ontogeny of information: developmental systems and evolution. Cambridge: Cambridge University Press.
Ruse, Michael. 2003. Darwin and design: does evolution have a purpose? Cambridge, MA: Harvard University Press.