Probability and the philosophies of science: A realist view

Like causality, probability is a critical concept in the conflict between contending philosophies of science. Unlike causality, a canonically `realist' view of probability appears elusive. This paper examines and strengthens the connections between realism and the epistemological theory of probability (EP), sometimes known as probability as logic or plausible reasoning. Following the likes of Keynes, Jeffreys, Pólya, and Jaynes, the EP tradition provides a framework for the study of non-demonstrative logic which hinges on an implicit concept of logical structure. EP advanced historically via critiques of positivism in physics and of the scepticism of Hume and Popper. EP also shares with realist philosophy a critique of a characteristic feature of empiricist philosophy—its explicit conflation of ontology and epistemology. To illustrate the normative value of this framework, I apply Pólya's theory of analogy to a portion of Galileo's classic argument that the earth is in motion.