Probability, Objectivity, and Induction

The main purpose of this article is to use Ayn Rand’s analysis of the meaning of objectivity to clarify the much-discussed question of whether probability is “objective” or “subjective.” This results in a classification of probability theories as frequentist, subjective Bayesian, or objective Bayesian. The work of objective Bayesian E. T. Jaynes is emphasized, and is used to provide a formal definition of probability. The relation between probability and induction is covered briefly, with probability theory presented as the basis of inductive inference.