Here is one way that philosophers and biologists sometimes speak of Darwin’s explanatory innovation: ‘Eyes, organs of echolocation, camouflage and the like are all wonderful instances of contrivance, of complex adaptation, of good design. Paley and the other natural theologians sought to explain this good design by appeal to an intelligent designer. Darwin, on the other hand, offers us a superior explanation for the appearance of this same property: Darwin shows us that we can explain good design through the action of selection. Indeed, selection is the only process that can explain good design in nature. And that is why evolutionary biologists can continue to use a version of the argument from design called the argument from biological design: when we see an instance of good design in nature, we should infer not the guiding hand of God, but the hand of selection at work.’