How is the argument from design supposed to work?
Three of Philo's main lines of attack rest on the claim that there is simply not enough evidence in nature to allow the empirical theist to draw the conclusions he wishes to draw. The first line of attack shows that there is nothing in the natural evidence to indicate that God has any of the natural attributes typically ascribed to him. Allowing, for the sake of argument, that the world is a machine and that its cause must be some intelligent designer, there is nothing about this machine to indicate that the designer is infinite, perfect, one in number, or incorporeal. For all the evidence tells us our God could be stupid, could have a body, or could even be a team of minor deities working in unison. A similar line of attack is used for God's moral attributes. For all the evidence tells us, God might not even be very nice.
Philo also uses the lack of evidence in a third line of attack. He attempts to show that the evidence available to us from the natural world could actually support any number of analogies equally well, not just an analogy to a machine. For instance, the evidence would support an analogy between the universe and an animal or even a vegetable.