You: Let me try another example, then. A maniac may find that a stolen automobile is useful for killing innocent people. It is certainly easier to kill people on a crowded sidewalk with a car than with one's bare hands, and the maniac can make a speedy getaway afterwards. The car serves a useful purpose to the maniac, so can we assume that cars are manufactured to kill innocents.

Aaron: You certainly enjoy trying to irritate me with ridiculous examples, don't you? What you have shown me is nothing more than the misuse of an object that was designed for another purpose. It does not prove that the object was not designed, only that it can be used in other ways than it was intended.

Aaron: Your argument assumes that the object was designed in the first place.

Let us imagine that, instead of a watch, I find a pointy rock buried in the desert. That rock might be useful for cutting skins to make clothing or for breaking open shellfish, but that does not prove that the rock was made pointy for a purpose. The rock might also be quite handy for killing people on a sidewalk, but, because we do not know if it was designed for some specific purpose, we cannot say that this is a misuse of the object.

Aaron: We are getting rather far afield, aren't we? It is obvious that an automobile or a pocket watch is a designed object, so we can tell that it is being used either correctly or incorrectly.

You: That is true, but it has nothing to do with the point you were trying to make. Your point was that things that serve a useful purpose must be designed for that purpose. If I find a bone in the ground, I might decide that it could me made into some tool, but that tool will have nothing to do with its original use to the animal it came from. I cannot prove that the bone was designed specifically to help an animal stand any more than I can prove that a pointed rock was designed to help me make clothing. Both could be the result of natural processes and completely without design.

Aaron: You don't seem able to see the distinction between something that is simple, such as the rock, and can occur by chance and something complex, like an animal or a watch, that could not possibly appear by chance. Before we get off on that tangent, let me prove to you that nothing complex can appear spontaneously. This will solve the problem you are having, I am sure.

You: Fine.