6 - A New Fine-Tuning Argument for the Multiverse

Summary

This chapter has two combined aims. First, I point out that the standard fine-tuning argument for the multiverse, as discussed in the previous two chapters, differs crucially from paradigmatic instances of anthropic reasoning such as, notably, Dicke's and Carter's accounts of large number coincidences between large numbers in cosmology. The key difference is that the standard fine-tuning argument for the multiverse treats the existence of forms of life as calling for a response and suggests to infer the existence of a multiverse as the best such response. Anthropic reasoning of the type championed by Dicke and Carter, in contrast, assumes the existence of forms of life as background knowledge when assessing whether the large number coincidences are to be expected, given the competing theories. The second aim of this chapter is to propose a new fine-tuning argument for the multiverse, which – unlike the standard one – is structurally similar to Dicke's and Carter's accounts of large number coincidences. The new argument turns out to have the virtue of being immune to the inverse gambler's fallacy charge.