Objections to the design argument

Here are two popular objections to the teleological argument:

He concedes that we often do make inferences to design (or, more appropriately, intention) in the sciences. For example, archaeologists do it when they discover artifacts. But the reason they can do this is that they already know something about the beliefs, desires and intentions of human beings. Using this background knowledge, they can specify how human beings might be expected to act and makes guesses about the artifacts they might be inclined to create. There is no analogous background knowledge when it comes to God.

http://commonsenseatheism.com/?p=9960

Evolutionary opportunism also results in suboptimal functions and structures. As stated before, in gradually evolving a new function, organisms must make do with what they already have. Thus, functions are likely to be performed by structures that would have been arranged differently (e.g. more efficiently) if the final function were known from the outset. "Suboptimality" does not mean that a structure functions poorly. It simply means that a structure with a more efficient design (usually with less superfluous complexity), could perform the same final function equally well.

http://www.talkorigins.org/faqs/comdesc/section3.html

The problem with these two objections is the way they cancel each other out. If you can’t detect divine design because you can’t infer divine intent, then you can’t say an organism suffers from a design defect. You’d only be in a position to know the design was defective if you know what God intended to achieve. You can’t say an agent missed the target unless you know what he was aiming for.