Pixel42
Schrödinger's cat
I thought the point of the argument from design is the fact that there isn't an important difference between the living stuff and the watch; you "know" as soon as you see the watch that it was designed, so you should "know" the equally complex living stuff was also designed.
But there is an important difference, of course, which is that the living things can reproduce themselves and the watch cannot. There aren't any male and female watches who mate to produce lots of baby watches which are similar to their parents and yet differ from each other, on which natural selection can act. So for the watch there are indeed only two possible explanations: it either spontaneously assembled, which is clearly ridiculous, or it was intelligently designed. For living things, however, there is a third possible explanation: that they are the end result of millions of years of evolution by natural selection.
But there is an important difference, of course, which is that the living things can reproduce themselves and the watch cannot. There aren't any male and female watches who mate to produce lots of baby watches which are similar to their parents and yet differ from each other, on which natural selection can act. So for the watch there are indeed only two possible explanations: it either spontaneously assembled, which is clearly ridiculous, or it was intelligently designed. For living things, however, there is a third possible explanation: that they are the end result of millions of years of evolution by natural selection.