There are two hypotheses for an explanation for the fine-tuning (FT) of nomic behavior we observe, which permits the existence of intelligent life. These hypotheses are that there is a fine-tuner responsible for causing the nomic behavior and a non-fine-tuner hypothesis–anything but a fine-tuner.
The two competing hypotheses rise and fall on the same crux. One of the problems with falsifying ~FT is that whatever falsifier may be presented it could always be attributed to this idea of cosmic Darwinism, the evolution of the multiverse itself. Paul Davies criticizes the multiverse because he believes it could never be falsified simply because many worlds can be used to explain anything. Science would become redundant and the regularities of nature would need no further investigation, because they could simply be explained as a selection effect, need to keep us alive and observing. The danger of accepting an effectively unfalsifiable hypothesis is that science has no way to determine if the belief corresponds to reality. Historically, the scientific community has affirmed several instances of things that were in fact not true—for example, the universal ether. If it is the case that anything that resembles FT can be attributed to or assimilated by ~FT makes ~FT incredibly difficult to falsify—if not impossible. If ~FT is unfalsifiable it can never rest in empirical harm’s way. Here, the key point that needs to be falsifiable is the explanation of the multiverse (FT or ~FT) and not the multiverse itself.
 Davies, The Mind of God (New York: Simon & Schulster, 1992), 190.
 Michael Behe, “The Intelligent Design Hypothesis” in God and Design, Ed. Neil Manson (New York: Routledge, 2003), 289.