Often we hear mentioned the criticism that unless Intelligent Design proponents can specify who the designer of their alleged irreducibly complex biological structures and processes is, their theory is mere speculation and not science. Not only do the critics demand to know who the designer is but also how the designer actually accomplished such wondrous feats of engineering.
This demand to identify the designer is misguided, however. It is certainly possible to conclude that we are observing an intelligently designed phenomenon without knowing anything about who designed it or the process the designer employed.
Bill Dembski makes this point in chapter 32 of his book The Design Revolution. The salient passage is quoted below:
Consider the case of SETI, the Search for Extraterrestrial Intelligence. If we were to receive a radio signal from outer space representing a long sequence of prime numbers (as in the movie Contact), we would know we were dealing with an intelligence-indeed, SETI researchers would be dancing in the streets, the New York Times would be trumpeting the discovery, and Nobel Prizes would duly be awarded.
But what exactly would we know about the intelligence responsible for that signal? Suppose all we had was this signal representing a sequence of primes. Would we know anything about the intelligence's purposes and motives for sending the primes? Would we know anything about the technology it employed? Would we know anything about its physical makeup? Would we even know that it was physical? Our evidence for design in this case would be entirely circumstantial. We would be confronted with an effect but be unable to trace back its cause.
Consider a more extreme example still. Imagine a device that outputs 0s and 1s for which our best science tells us that the bits are independent and identically distributed with uniform probability. (The device is therefore an idealized coin tossing machine; note that quantum mechanics offers such a device in the form of photons shot at a polaroid filter whose angle of polarization is 45 degrees in relation to the polarization of the photons-half the photons will go through the filter, counting as a "1"; the others will not, counting as a "0.")
Now, what happens if we control for all possible physical interference with this device, and nevertheless the bit string that this device outputs yields an English text-file in ASCII code that resolves outstanding mathematical problems, explains the cure for cancer, and delineates undreamt of technologies?
The output of this device is therefore not only designed (and obviously so) but also exceeds all current human design. Yet our best science has no way of prescribing a causal account for how this design was imparted. By Hume's logic, we would have to shrug our shoulders and say, "Golly, isn't nature amazing!"
If it were demonstrated beyond any reasonable doubt that the bacterial flagellum is a mechanism which must have been somehow designed by an intelligent architect of some sort, it would be foolish to refuse to acknowledge the fact in science journals simply because we don't know how it was done or who the designer is.
Indeed, Brian Greene points out in his book The Fabric of the Cosmos that theoretical physicists often posit the existence of entities and phenomena which defy observation and any kind of physical description. Nevertheless, their existence is inferred from the need to satisfy our theories about why the world is the way it is. Some examples of such entities or phenomena are entangled particles, the Higgs field, the inflaton field, other dimensions, branes, and strings.
The demand that ID theorists identify their designer is a red herring which is itself designed to deflect attention from the persistent and uncomfortable fact that biological structures give the appearance of having been exquisitely designed for a purpose. Critics insist on being told who the designer is so as to divert scrutiny from the additional fact that mindless mechanisms are disappointingly inadequate to account for the degree of intricacy that abounds in every cell in our bodies.