In Paley’s argument for God’s existence, we find that Paley says quite clearly that his argument does not depend on our observing that adaptations are perfect.

Even if the watch we find keeps time imperfectly, we would still conclude that it was produced by intelligent design.

So, Paley concludes that the design hypothesis is overwhelmingly plausible even if we find that organisms are not perfectly adapted to their environments.

But the problem here is that Paley’s argument for the existence of an intelligent designer is a version of creationism that does not predict whether organisms will be perfectly or imperfectly adapted. We might formulate Paley’s minimalistic hypothesis like this:

H₄: Life has properties that are due to intelligent design.

But this hypothesis appears to be untestable—it is impossible to evaluate what H₄ tells us to expect when we look at organisms.

At this point, we need to evaluate H₄ using other criteria of adequacy for hypotheses. >>> Critical Thinking Principles