Examples below the fold.
Just for fun, I am going to employ the most sophisticated and beautiful of all logical arguments: the dilemma. The dilemma is a way of putting your opponent in a box; it is a way of showing him that, no matter what in fact is the case, his assumption leads to an unacceptable conclusion. Again, there are numerous ways of attacking the truth of a statement—this is only one of them.
If I am making this argument, here’s how I do it: There are only two kinds of rights: those that originate in divine law and those that originate in human law. If the claim is that same-sex marriage is a right originating in divine law, then it must be false, since (if it is addressed at all) it is precluded by the holy books of all major religions. If the claim is that same-sex marriage is a right originating in human law, then it must, again, be false, since the law of the land (at least in the United States) does not acknowledge it. Therefore, in either case—whether the appeal is to divine or human law—the claim is false.
Note the nice clean division of originating in divine law or human law. Only the very naive, inexperienced would not that the argument does not address interactions between divine law and human law, nor the other potential sources of rights. This is not valid argumentation, it is a rhetorical trick. Unfortunately, Cothran seems to think this is some sort of valid method. Maybe this is a matter of necessity. maybe the world of the creationist can't survive in a world of shades and colors.
Then he gives what he imagines to be a lesson in reducito as absurdum, attempting to show that a lack of testability does rule ID out of science:
The best place to look for scientific theories that are not falsifiable is physics. Everyone accepts that physics, and the theories that are included under it, are scientific. But many of them are not falsifiable—at least not now. The most famous of these is superstring theory. Superstring theory is the theory that particles and fundamental forces in the universe can be explained by the vibration of very tiny symmetrical strings. The problem is that the theory is not only not falsifiable, but, as some scientists have pointed out, it isn’t even conceivably falsifiable. Some of Einstein’s thought experiments (many of which he later set forth as full scientific theories), the scientific status of which have never been questioned, are not falsifiable either.
Your opponent could swallow hard and say that these things are not science, but he will know he is on shaky ground—and he will know you know he knows it.
Note how he projects his own limited world-view onto others. In fact, I don't feel that I am at all on shaky ground in saying that any hypothesis which is not testable is not relevent scientifically. However, there are differences between hypotheses that are inherently untestable (Intelligent Design can not be falsified under any conditions) and those that are untestable under current technology, but may eventually prove testable. Neither is a part of science today, but the latter can at least eventually be scientific.