I have recently become more aware of a range of views within the science and faith debate which has been termed "design theory". My impression is that such views are more common within the US than here in the UK, and are evident in many of the articles on the Origins website as well as being implicit in books like "The Fingerprint of God" by Hugh Ross (that, at least, was my impression). Put simply, design theory offers itself as a scientific theory including the action of a designer within evolutionary descriptions of the origin of life. I have several reservations about the validity of such an approach to how science and Christian faith are related, but first of all I shall try to describe design theory more fully.
Description of Design Theory
I have got most of my information on design theory from the Origins website, particularly articles by William Dembski entitled "What every thologian should know about creation, evolution and design" and "Science and design". I have drawn heavily on this material, and I hope I have not misunderstood it and as a result unfairly represent the authors views.
First of all, I shall follow Dembski by stating what design theory is not. It is not young-earth creationism, nor does it require any particular interpretation of the opening chapters of Genesis. Nor is it progressive creationism, in which God intervened at specific points in natural history to create new kinds of creatures from scratch. It is not even anti-evolutionist in a strict sense; design theorists would accept that organisms experience evolutionary change over the course of natural history without placing any limit on the extent of such change.
Design theorists do not, primarily, see themselves debating with theologians but evolutionary biologists. What they are offering is an alternative scientific explanation of the facts of the evolution of organisms, an alternative to the claim that all change is driven by purely naturalistic processes totally devoid of purpose. Design theory starts from a critique of neo-Darwinianism as an empirically inadequate scientific theory rather than any system of religious belief. This critique of neo-Darwinianism is basically that it is not well supported, is limited in it's explanatory power and fails to account for the full sweep of natural history.
In place of the purely naturalistic, purposeless view of evolution offered by neo-Darwinianism design theorists offer a theory in which design and purpose, and presumably therefore a designer, are intrinsic to evolution theory. In support of this claim design theorists show how design would have consequences for the evolutionary record and biological systems that could not be explained by neo-Darwinian approach. What is offered is a scientific criterion for detecting design within the natural world, similar to criteria used by SETI to identify intelligent signals from the natural background of extra-terrestrial radio signals. This is the criterion of irreducible complexity developed by Michael Behe; a system is irreducibly complex if it consists of several interrelated parts such that removing a single part destroys the systems functionality completely. This is compared to cumulative complexity, in which components can be successively removed without complete loss of function. While many human constructs are irreducibly complex as a result of design, the question is can irreducibly complex systems in nature (for example many biochemical pathways) be produced by purely random, naturalistic processes or are they evidence for design? Design theorists state that such systems "cannot be explained by the Darwinian mechanism, nor indeed by any naturalistic evolutionary mechanism proposed to date" (Dembski). It is claimed that this criterion is a reliable means of detecting design from the observed features of the world, although not achieving the status of logical demonstration it "does achieve a statistical justification so compelling as to demand assent" (Dembski, ibid).
The attraction of design theory to Christians is obvious, it allows the acknowledgement that scientific descriptions of the world demonstrate the power and nature of God (Romans 1:19-20) and affirming Him as Creator without committing intellectual suicide by accepting an overly literal interpretation of the opening chapters of Genesis. It also reintroduces the concepts of purpose and goals, as well as genuine ethics and morality (as opposed to the apparent morality some evolutionary theorists try to explain), into scientific discussion. But, for all its attractions, the questions are is it a necessary or useful approach?
An Assessment of Design Theory
The first thing I noted was that the critique of neo-Darwinianism presented seems to be primarily directed at views expressed by Richard Dawkins, and others with similar views. Design theorists are not alone in their criticisms, others have offered similar critiques while still remaining firmly within the standard theory of a purely naturalistic evolutionary process. As an alternative to the views of Dawkins et al, design theory is not the only alternative position.
An obvious criticism of design theory, and one which the proponents of this view are strenuous to deny, is that they are presenting a God-of-the-gaps. The question is, how does a designer influence the evolutionary process? Design theorists would reject a view of God stepping in at specific stages in evolution to create entirely new species (progressive creationism) or complete biochemical systems, but rather that the designer provides a goal to evolution, an additional selection criterion on which evolution works. This begs the question, if God doesn't create the irreducibly complex biochemical systems, that design theorists appeal to as evidence for design, then how did they come to be formed? Presumably they were formed gradually over time, which is precisely what conventional evolutionary theory would claim. It therefore follows that the formation of irreducibly complex systems is an irreversible process; just because components of such systems cannot now be removed without completely destroying the functioning of the system does not mean that those components could not have been formed and assembled into the current system (and continue to evolve into other systems with other functions) over time. To provide evidence (let alone enough evidence to demand assent) that a particular system shows unmistakable signs of design would seem to be all but impossible; and a single example of design could be easily dismissed as being just incredible chance, many such examples would be needed for design to be accepted as a part of a scientific description of the world.
So, if there aren't any compelling reasons to accept design theory from a scientific viewpoint, are there any from the viewpoint of the Christian faith? Specifically, does the passage in Romans 1:19-20 ("God's invisible qualities - his eternal power and divine nature - have been clearly seen, being understood from what has been made") require that evidence for the work of God be apparent in scientific descriptions of the world? If scientific descriptions were the only valid ways of describing the world then we probably would expect this, but of course other descriptions of the world from (for example) the arts, theology and philosophy do clearly reveal something of God. That "the only universally valid form of knowledge within our culture is science" (Dembski) does not mean that we have to introduce design into science so that His hand in creation can be seen. It would seem far more reasonable (and healthy for society) that the validity of other fields of knowledge be reclaimed and the insights of these fields which reveal God in creation be reasserted.
What alternative to design theory is there, apart from young earth creationism and atheistic evolutionism, that would allow one to take seriously the scientific evidence for evolution and the Biblical witness to the nature of God, humanity and the universe? I take both scientific and Biblical (and reasoned reflection thereon) descriptions of the world as being seperate, complementary views. Each is, within its own reference frame, a complete description of the world that does not require (although would benefit from) the insights of the other. The two positions are, in places, apparently contradictory especially when one is held as being superior to the other. So, scientific theories are atheistic in that they do not (and indeed I'd say should not) require reference to God, that does not however require scientists to be atheists. And, although evolution is governed by chance processes without purpose, that doesn't mean that there is no purpose only that such purpose would not be evident in a scientific description of the world.
In conclusion, although design theory is a more reasonable approach than either young earth creationism or atheistic scientism, I find that it is still somewhat lacking. As a scientific theory it has some serious problems, and there is a more satisfactory approach to taking both science and the Christian faith seriously.