Paley s analogy between eye and watch is not close enough, for vastly different causes could answer to this effect. Hume s third main criticism of the teleological argument is that the universe s origin was a one-time occurrence without parallel . But the ascription of cause can only be made only after repeated experience of similar cases. In order to assign an intelligent cause to the universe we would have to have had repeated experience of the origin of worlds. The fitness of Paley s machine analogy has been revived by recent science.
Organisms show a remarkable complexity suggestive of design.
While other explanations are possible, none can afford more than probability, and the design hypothesis more probable than any other.