PZ Myers posted on why creationists should not be debated, and Vox Day offered a response, which I address below:
Myers:It pits oratory against science in a venue where you'll be judged on your rhetoric.
Vox: Of course, if you actually know your stuff cold, it shouldn't be a problem.
Right, that's why we see so many scientists in arenas where rhetoric counts so much, like sales and politics. Debate is a skill like any other, and it correlates far more with the ability to think and speak quickly, than it does with being accurate. This is, in fact, why creationists insist on live spoken debates rather than written ones. In written debates, every point can be fully addressed, complete with references, whereas in a live debate, a fast speaker can overwhelm his opponent (ie the Gish Gallop, see below).
Myers: It gives publicity to creationists.
Vox: Oh no! You would think that allowing them to expose their stupidity, which we are told ad infinitum is just painfully obvious, would be something PZ and company would support.
Vox is attacking a straw man here. What we on the scientific side of the debate say ad infinitum is not that the creationists are stupid, but that they are unscientific, and that they are wrong. Debating them as equals will give the impression to the casual observer that they ARE equals. The trappings of scientific validity is what the creationists desire above all else. They are unable to earn it as legitimate science does, through experimental validation and peer review, so it is important to not allow them to do an end run around the process.
Myers: Creationists can generate more lies more quickly than you can refute.
Vox: Not if you know your subject well and are capable of articulating it properly.
Bullshit. "Archaeopteryx was a fake" takes 4 words to assert. Refuting it takes considerably more time, as refutations to most poor arguments do. Any logical fallacy takes longer to explain than to use. Also, repeating the point from earlier, being articulate is not a very valuable talent for a researcher. It IS a valuable talent to being a lawyer, and not coincidentally, several prominent IDers/creationists (Philip Johnson, Casey Luskin) are attorneys. A scientist not speaking well off-the-cuff not only doesn't say anything about the legitimacy of his POV, it is pretty predictable.
Vox:Of course, if all your answers rely on claiming that no one can possibly understand what you're saying without a PhD, you might as well recognize that you're always going to lose in any venue. In fact, why even talk, since no one can understand you anyhow?
Creationists are fond of trotting out these straw men, but you'll notice there are almost never references to any real scientist talking like this. Three guesses as to why.
Myers:Debates artificially give equal time to two sides, falsely elevating creationist trivia to equality with scientific substance.
Vox: Of course, debates in which only one side is allowed to talk isn't really a debate now, is it? Again, we see that the evolutionists simply can't defend themselves, so they demand an unfair playing field.
Quite the contrary. The scientific playing field is very open. It is in the peer-reviewed literature. Of course the creationists avoid that like the plague because they lose in that arena (you know, the one where evidence and all matter). There is a reason the scientific community chooses a public written medium over a spoken one like debates: it is far more effective for highly technical and complicated exchanges.
The best short response for a scientist challenged to a debate in his field is to accept: as long as it is in writing. A written debate has a ton of advantages over a live spoken one:
1) Filibustering/Gish Galloping is impossible.
2) All points get their due attention, and lies can be exposed.
3) It draws a larger audience.
4) The audience has time to ponder the points made fully and can return as needed for a reread.
Of course, all of the above (except #3) are exactly what creationists are trying to avoid, which is why they insist on spoken debates in the first place.