Mass phenomena to which the theory of probability does not apply are, of course, of common occurrence. - Richard von Mises

Apart from this older generation, there is scarcely a modern mathematician who still adheres without reservation to the classical theory of probability. The majority have more or less accepted the frequency definition.

The theory of probability can never lead to a definite statement concerning a single event.

The whole financial basis of insurance would be questionable if it were possible to change the relative frequency of the occurrence of the insurance cases (deaths, etc.) by excluding, for example, every tenth one of the insured persons, or by some selection principal.