Probability, explanation, and reasoning

Abstract

Three topics are discussed concerning the application probability and explanation to the confirmation of theories. The first concerns the debate over prediction versus accommodation. I argue that we typically have reason to be more confident of a theory given that it was constructed independently of the knowledge of certain data than if it was designed to accommodate those data. The second concerns the puzzle of the apparent 'fine-tuning' of the universe for life. I argue that the fact that our universe meets the extremely improbable yet necessary conditions for life provides no evidence for the thesis that there are, or have been, very many universes. The third chapter concerns the need to explain the existence of life. I argue that if life's existence needs an explanation at all, the place to look is in a teleological explanation. If this option is rejected, we should be content to see the origin of life as an extremely improbable fluke.