This is the gist of my recent reply to a post on Objectivism Online about debating creationists, which thought might be of interest to others who encounter those pesky creatures:

Arguing with creationists – that way lies madness. Many years ago I had an extended argument with a creationist (by mail – yes, children, there was an era before email ? ) and at one stage, I even convinced him. But then he slowly slid back and the convincing didn’t stick.

One of the problems with creationists is that the creationist literature is rife with errors. If the errors were true, then they would actually have a case! But what I found in the course of arguing, by looking up the primary literature quoted by creationist luminaries, was almost all of it was either misquoted, out of context in a way that changed the meaning, or otherwise inaccurate. Creationist “intellectuals” in general troll the literature for word bites they can use, without attempting to understand their real meaning. And the problem with that is that short of taking apart every claim, it is hard to get to a creationist: they just jump from one to another and you usually find yourself running in circles.

Unless you are dealing with a creationist actually open to having their mind changed (possible, but rare), the best you can do is point them in the direction of some of the books written by scientists that refute the creationist arguments (yes, it takes a book’s-worth, hence the impossibility of doing it verbally) for the details, and just approach it from a higher level. Things that you might find useful are:

• Evolution is not random: the raw material (mutation, gene shuffling etc) is random but the directional accumulation is non-random via natural selection.
• Natural selection is not a tautology: it is a direct and in fact necessary consequence of reality and causality, of the fact that organisms have to survive and reproduce in the real world, and that real world imposes conditions on what they have to do.
• Theories are not inferior to “facts”: theories are explanatory frameworks, and can themselves be facts (e.g. the “theory” of universal gravitation).
• Complex organs (and organisms) do not have to arise by “chance” or all at once: they arise by accumulations of smaller changes, each in itself an advantage in its own right (or at least, not a severe disadvantage – many changes actually happen by random drift). Creationists do dispute this (hence “irreducible complexity”) but:
  • In nearly all cases of alleged irreducible complexity, there are plenty of examples among living creatures or fossils that there is a sufficient range of complexity, all perfectly functional, for the change from simple to complex to have evolved naturally. Examples are the classic case of the eye (in nature, a myriad of forms of increasing complexity from pigment spots to vertebrate eyes); and the mammalian jaw (an excellent series of fossils showing how, yes, the lower jaw bones of reptiles did evolve into the single lower jaw + inner ear bones we possess, despite the apparent unlikelihood of doing that).
  • In some cases, the structure may be so ancient and/or non-fossilisable that we have no direct information like that. But “I do not know how this could have evolved” or even “I cannot believe this evolved!” is not proof that it couldn’t. Especially in the light of all the irrefutable evidence of what can and has evolved.
  • A good example, I forget where I read it, is that of an arch. It might be impossible, looking at a finished structure, to imagine how it could have been constructed piece by piece. But that doesn’t mean it wasn’t. In the case of evolution, things get mixed and matched and something that evolves for one function can be co-opted for a quite different one (many examples are known). In the case of an arch, you canbuild one stone by stone: you use a scaffold, then remove it when the arch is complete. Same kind of thing in evolution. Unless we have fossils, we see the end point, not the steps, and the steps that constructed that endpoint may not be obvious.
• There are transitional fossils: so many that creationists should be embarrassed to still be creationists. The fossil record is never going to be complete (the number of fossil species identified is far less than the number alive today, which shows you the scale of the problem of getting complete evolutionary sequences), but even then it is good enough to crush creationism. Good examples are the recent findings on birds (a whole menagerie of creatures from feathered raptors to obvious birds) (Archaeopteryx alone was enough for any honest mind, but now…); the transitions from fish to amphibian, amphibians to reptiles, and reptiles to mammals; well, the list goes on and on with less grand changes, such as the evolution of aquatic whales from land-dwellers, not to mention human beings from apes.
  • In some cases, fossils with transitional forms are dated after the time when the transition must have occurred. However this is neither surprising nor a problem. For the reasons stated above – each stage in a transition is viable in its own right – it is not surprising that transitional forms live on while others of their type moveon. We do after all see that all around us today. Chimps are approximately structurally transitional between monkeys and humans – they have a common ancestor with us but have diverged less from the ancestral form. But they are still here. Ditto all the way back to bacteria.
  • The “point” of such belated transitional forms is not to prove evolution occurred: but it does prove that transitional forms existed and were viable. And they are a prediction of evolutionary theory in their own right, as demonstrated above.
• The Second Law of Thermodynamics (entropy) and (a related topic) Information Theory do not contradict evolution. Earth is not a closed system, it is bathed in sunlight which provides the bulk of the energy living things need to live, grow – and evolve. Each living thing itself goes against entropy by the fact that it not only survives but grows and develops. And yet, they are here. For the same reason.

I think that covers the bulk of the kinds of arguments creationists present. If they want to argue the details – point them to a good book. And a good book, almost by definition, is one not written by a creationist ?