ABSTRACT
Probability is usually contrasted with certainty, and both terms apply only either to judgments or to propositions. In most of the affairs of life we have to come to a decision on evidence which is not conclusive, so that our judgments are not certain, only more or less probable. “Probability,” as Bishop Butler has said, “is the very guide of life.” The mathematical treatment of probability is concerned almost exclusively with the measurements of probability. Influenced by the empirical tendencies of a scientific age, and contemptuous of the high a priori road favoured of theologians and philosophers, writers on Probability have been tempted to base all calculations of probability on frequencies. Probability is concerned even with single events and small groups or series of events, while frequencies always refer to large classes, or long series of events, to what happens “in the long run.”
