Fine-Tuning and the Multiverse Argument Against Naturalism

Abstract

The multiverse is often invoked by naturalists to avoid a design inference from the fine-tuning of the universe. I argue that positing that we live in a naturalistic multiverse (NM) makes it plausible that we currently exist in a problematic skeptical scenario, though the exact probability that we do is inscrutable. This, in turn, makes agnosticism the rational position to hold concerning the reliability of our reasoning skills, the accuracy of our sensory inputs, and the veracity of our memories. And that means that agnosticism is also the rational position to hold concerning all the beliefs derived from those sources, which includes nearly all of them. Consequently, there is an unacceptable skeptical cost to accepting a NM, thereby requiring a rejection of the NM as a counter to fine-tuning or a rejection of naturalism itself.