When I go and stick my neck out on evolution and liberal blogs not only are the attacks fierce, but so also are the irrational remarks and even censorship that pervade conversation that might otherwise be pleasant. These folks seem generally decent but often have a difficult time carrying on a dialogue with someone who holds another world view. I won’t name names here. That wouldn’t be polite. All I wish to do is delve into the argumentation methods used to denounce others. I hope that this evaluation approach will help you as you engage the world for Christ by helping you understand something about the mind and motivations of those you encounter.
When it comes to the question of evolution (big E or little e), without addressing the merits of the issue, the question of argumentation always comes into play. For instance, those of us who are overtly presuppositional make certain claims about the universe. But things are not so tidy in the world of scientists and especially not so in the world of the amateur philosopher. As an example, Jerry Coyne made a core presuppositional remark regarding his understanding of evolution:
If speciation is true, for instance, then common ancestry must also be true. (Why Evolution is True, p. 14)
This is not an evidential statement. Dr. Coyne has built a stair-step of apparent deductive necessity. In his view, if the former is ever the case then the latter, which is much broader in scope, must also be the case. If at any time any species can develop (by whatever model) then all species must have developed in this or similar fashion.
In order for this to be a must the argument requires a rejection of any alternative. If speciation is ever true then creation (special or general) is never true. I won’t argue against this in terms of a b&w fallacy. It isn’t. It is a simple statement regarding correctness and incorrectness as he sees it.
The argument does not include evidence. Speciation here is not, as I read it, an argument from evidence, though he does argue for speciation from evidence at other times. As stated, speciation is set up as a sort of equivalent to common ancestry. That is the core question that is argued: What is our ancestry? Though stated specifically, Dr. Coyne’s argument is a presuppositional argument for a metaphysical naturalism. Common ancestry sits as a euphemism for that purpose. Common ancestry is his analogy for naturalism. I suspect he might agree.
Dr. Coyne does argue from evidence to prove speciation. He takes a core Darwinian position. In this sense he is also an evidentialist. That’s ok. That’s what evidence is for – proving assumptions. But evidence is never a proof of presuppositions. Presuppositions come with no contingencies or dependencies. They stand alone. And that is the weakness of the must-ness of his position. He can prove speciation (to which I do not object in principle, though I would contend that there are models better than Darwin’s model) but he cannot prove naturalism.
This is the challenge that we face in defending the faith against illogic. It is not simply Christians who hold to presuppositions. The principle is not one that we own. What we do well to do in these cases is to show that there is more to life and a defense of anything than the preponderance of evidence. To do this makes us better thinkers and better representatives of intelligence.