Fine-Tuning Problems for Single-Universe Naturalists

The ‘fine-tuning’ of the universe has led many individuals to infer the existence of a designer, a multiverse, or something else that can account for it. Yet, proponents of a view known as single-universe naturalism have certain responses they can make to block the inference from fine-tuning to a designer or multiverse. In this paper, I argue that these responses fail to block this inference. For instance, I raise and develop the uncertainty problem, which pertains to single-universe naturalists who deny that we can assign any probability to fine-tuning. I also argue that there are problems with other responses that single-universe naturalists can make to try to account for fine-tuning, such as the response that the universe’s constants are necessary or the response that there are no probabilistic mechanisms responsible for fine-tuning.