Well, Brownback addresses his many critics in a New York Times op-ed. He starts off by the saying the right things, such that it is wrong to "drive a wedge between faith and reason". But then he says the following:
"If belief in evolution means simply assenting to microevolution, small changes over time within a species, I am happy to say, as I have in the past, that I believe it to be true. If, on the other hand, it means assenting to an exclusively materialistic, deterministic vision of the world that holds no place for a guiding intelligence, then I reject it."Now, as noted over at Mirror of Justice by both Rick Garnett and Eduardo Penalver, this is an exercise in obfuscation. Why? Because he is confusing two issues: the notion of an infinite creative intelligence, and "microevolution, small changes over time within a species". He is speaking in code, easily understandable to the proponents of the American design movement.
We need to be careful careful when we use the term "intelligent design". At some fundamental level, Catholics must believe in an "intelligent designer", as hand of the creator guides the evolutionary process. But it is important to note that the American-created "intelligent design" movement does not merely postulate that God is the Creator of everything out of nothing and guides all of creation (sensible), but encroaches on scientific territory by questioning the evidence for evolution (not so sensible). As pointed out by Jerry Coyne in the New Republic a few years back, a key premise of intelligent design is that organisms appeared simultaneously, and have existed that way ever since. While they accept the idea of "microevolution" (within-species changes), the intelligent design crowd casts doubts on "macroevolution" ("large scale changes, leading to new levels of complexity".)
Seen from this angle, Brownback's strange choice of wording makes more sense. As Penalver points out, the senator is trying to have his cake and eat it, by appealing to reason, but being careful enough not to antagonize his fundamentalists backers who love intelligent design. Notice that the denial of evolution is concentrated in a small group of American evangelicals, and is not an issue in any other country. The reason is straightforward. American fundamentalists believe God's word is a fixed text rather than reason incarnate, making the complementarity between faith and reason less essential. I think that Brownback, a Catholic covert from evangelical fundamentalism, still may have some distance to travel in this area.