The Argument from Harmony: Aquinas here determines that things in general tend to tend toward an end, even when they lack of knowledge, and do so with some efficiency. For this reason, he states, things must be guided by someone or something that possesses intelligence, and this is what he calls God. He hypothesizes here that things tend toward disorder when left to their own devices, a premise he neither addresses nor defends, and that for them to work toward an end there must be a God who guides them. Here he poses the question, assuming that all things are aided by a supreme being, and that this aid is what prevents disorder from occurring, and that further, the fact that things do not tend toward disorder proves that there is a God. The five a posteriori arguments presented by Thomas Aquinas are clearly insufficient. In the first as in the second, he contradicts himself, accepting that there must be a first mover or cause, whereas all things must have a cause. In the third, he assumes that the possibility of non-existence indicates the inevitability of non-existence at some point in the past. In the fourth he has a good argument, but he doesn't.