The theory of probability can never lead to a definite statement concerning a single event. - Richard von Mises

It has been asserted - and this is no overstatement - that whereas other sciences draw their conclusions from what we know, the science of probability derives its most important results from what we do not know.

It seems to me that if somebody intends to marry and wants to find out 'scientifically' if his choice will probably be successful, then he can be helped, perhaps, by psychology, physiology, eugenics, or sociology, but surely by a science which centres around the word 'probable'.

Equally possible cases do not always exist, e.g, they are not present in the game with a biased die, or in life insurance. Strictly speaking, the propositions of the classical theory are therefore no applicable to these cases.