The Distinction Between Natural and Non-Natural Designers

But isn't there an evidentially significant difference between natural and non-natural designers? It seems that this worry is really what's behind the desire to front-load all the design in nature. We all have experience with designers that are embodied in physical stuff, notably other human beings. But what experience do we have of non-natural designers? With respect to intelligent design in biology, for instance, Elliott Sober wants to know what sorts of biological systems should be expected from a non-natural designer. What's more, Sober claims that if the design theorist cannot answer this question (i.e., cannot predict the sorts of biological systems that might be expected on a design hypothesis), then intelligent design is untestable and therefore unfruitful for science.

Yet to place this demand on design hypotheses is ill-conceived. We infer design regularly and reliably without knowing characteristics of the designer or being able to assess what the designer is likely to do. In his 1999 presidential address for the American Philosophical Association Sober himself admits as much in a footnote that deserves to be part of his main text ("Testability," Proceedings and Addresses of the APA 1999, p. 73, n. 20): "To infer watchmaker from watch, you needn't know exactly what the watchmaker had in mind; indeed, you don't even have to know that the watch is a device for measuring time. Archaeologists sometimes unearth tools of unknown function, but still reasonably draw the inference that these things are, in fact, tools "

Sober is wedded to a Humean inductive tradition in which all our knowledge of the world is an extrapolation from past experience. Thus for design to be explanatory, it must fit our preconceptions, and if it doesn't, it must lack epistemic value. For Sober, to predict what a designer would do requires first looking to past experience and determining what designers in the past have actually done. A little thought, however, should convince us that any such requirement fundamentally misconstrues design. Sober's inductive approach puts designers in the same boat as natural laws, locating their explanatory power in an extrapolation from past experience. To be sure, designers, like natural laws, can behave predictably. Yet unlike natural laws, which are universal and uniform, designers are also innovators. Innovation, the emergence to true novelty, eschews predictability. It follows that design cannot be subsumed under a Humean inductive framework. Designers are inventors. We cannot predict what an inventor would do short of becoming that inventor

But the problem goes deeper. Not only can't Humean induction tame the unpredictability inherent in design; it can't account for how we recognize design in the first place. Sober, for instance, regards the intelligent design hypothesis as fruitless and untestable for biology because it fails to confer sufficient probability on biologically interesting propositions. But take a different example, say from archeology, in which a design hypothesis about certain aborigines confers a large probability on certain artifacts, say arrowheads. Such a design hypothesis would on Sober's account be testable and thus acceptable to science. But what sort of archeological background knowledge had to go into that design hypothesis for Sober's inductive analysis to be successful? At the very least, we would have had to have past experience with arrowheads. But how did we recognize that the arrowheads in our past experience were designed? Did we see humans actually manufacture those arrowheads? If so, how did we recognize that these humans were acting deliberately as designing agents and not just randomly chipping away at random chunks of rock (carpentry and sculpting entail design; but whittling and chipping, though performed by intelligent agents, do not). As is evident from this line of reasoning, the induction needed to recognize design can never get started.

My argument then is this: Design is always inferred, never a direct intuition. We don't get into the mind of designers and thereby attribute design. Rather we look at effects in the physical world that exhibit the features of design and from those features infer to a designing intelligence. The philosopher Thomas Reid made this same argument over 200 years ago Lectures on Natural Theology 1780): "No man ever saw wisdom [read "design"], and if he does not [infer wisdom] from the marks of it, he can form no conclusions respecting anything of his fellow creatures.... But says Hume, unless you know it by experience, you know nothing of it. If this is the case, I never could know it at all. Hence it appears that whoever maintains that there is no force in the [general rule that from marks of intelligence and wisdom in effects a wise and intelligent cause may be inferred], denies the existence of any intelligent being but himself." The virtue of my work is to formalize and make precise those features that reliably signal design, casting them in the idiom of modern information theory.

Larry Arnhart remains unconvinced. In the most recent issue of First Things (November 2000) he claims that our knowledge of design arises not from any inference but from introspection of our own human intelligence; thus we have no empirical basis for inferring design whose source is non-natural. Though at first blush plausible, this argument collapses quickly when probed. Piaget, for instance, would have rejected it on developmental grounds: Babies do not make sense of intelligence by introspecting their own intelligence but by coming to terms with the effects of intelligence in their external environment. For example, they see the ball in front of them and then taken away, and learn that Daddy is moving the ball -- thus reasoning directly from effect to intelligence. Introspection (always a questionable psychological category) plays at best a secondary role in how initially we make sense of intelligence.

Even later in life, however, when we've attained full self-consciousness and when introspection can be performed with varying degrees of reliability, I would argue that even then intelligence is inferred. Indeed, introspection must always remain inadequate for assessing intelligence (by intelligence I mean the power and facility to choose between options -- this coincides with the Latin etymology of "intelligence," namely, "to choose between"). For instance, I cannot by introspection assess my intelligence at proving theorems in differential geometry, choosing the right sequence of steps, say, in the proof of the Nash embedding theorem. It's been over a decade since I've proven any theorems in differential geometry. I need to get out paper and pencil and actually try to prove some theorems in that field. Depending on how I do -- and not my memory of how well I did in the past -- will determine whether and to what degree intelligence can be attributed to my theorem proving.

I therefore continue to maintain that intelligence is always inferred, that we infer it through well-established methods, and that there is no principled way to distinguish natural and non-natural design so that the one is empirically accessible but the other is empirically inaccessible. This is the rub. And this is why intelligent design is such an intriguing intellectual possibility -- it threatens to make the ultimate questions real. Convinced Darwinists like Arnhart therefore need to block the design inference whenever it threatens to implicate a non-natural designer. Once this line of defense is breached, Darwinism quickly becomes indefensible.

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