chance

Chance is frequently regarded as unreal, a mere reflection of human ignorance, due to be eroded by the onset of deterministic science. In ancient and medieval philosophy chance could be contrasted with divine purpose, and until the 18th century the concept was of little application, since nothing is strictly due to chance when God's purpose is shown in all creation. The equally ancient opposition between chance and science was eroded after the rise of statistics and probability theory in the 17th century. Probability became the ‘guide of life’ providing the tools with which to assess chances in insurance and gambling, discovering causal connections, finding rates of mortality, crime, and marriage, even before the onset of probabilistic theories in physics, such as statistical mechanics and then quantum mechanics . The problem of interpretation is that of deciding whether probabilities measure something ‘real’ or whether they merely reflect the beliefs of reasonable persons faced with various quantities of data (see personalism ). The widespread view that quantum mechanics is irreducibly probabilistic, so that quantum events do not merely manifest superficial randomness overlaying a deterministic basis, is the main stimulus to attempts to give theories of what chance ‘really is’, or of how fundamental laws of nature can have a probabilistic form. One difficulty lies in seeing how two universes that are the same in respect of the events that occur, might yet differ in the chance with which those events came about.