Design arguments are meant to establish the existence of a designer. This often occurs due to some property that indicates a sort of design.
However, in every instance we’ve ever made a legitimate design inference, we’ve already known that the designer exists and that the designer has the right motivations and abilities to create that item. For example, when we observe a person win four straight lotteries, it is not just the fact that it is improbable for a person to win four straight, but also the fact that we know people exist and that they are capable of cheating that allow us to make this inference.
The only case of a design inference that I can think of where we don’t already know the existence of something is the project to establish the existence of extraterrestrial life. The SETI project tries to look for signals and patterns to detect extraterrestrials. However, even in this case, even though we don’t know for a fact that aliens exist, we do know that the universe harbors life (aka us on this planet).
In the case of god, there doesn’t seem to be any background information indicating the mere possibility of a god existing. If one observes an outcome that is improbable and would be valuable to a particular kind of agent, it doesn’t by itself tell you anything about the probability of the very agent’s existence.
As such, even if the origin of life was extremely improbable, or the fine tuned constants were extremely improbable, or any other property in the universe was found to be extremely improbable, doesn’t it also follow that those events imply nothing about the probability of this designer actually existing?
Of course, if we already assumed that a designer existed and has the right capabilities, then it would be perfectly sensible to think that the universe was fine tuned for example. But that assumption is what we are trying to prove.
Does this mean that the design argument is ultimately circular?
