Abstract

The principle of causality or of determinism, and the notion of cause, are studied in the light of recent results in quantum mechanics. A definition of the concept of cause, loosely related to Lewis' counterfactual approach, is proposed. Then the question 'has every (physical) event a cause ?' is investigated. According to the orthodox quantum theory the answer to above question is negative. However, it is argued that there exist at least as many arguments in favor of a 'yes' (and thus of determinism) as of 'no' – arguments that are fully compatible with quantum theory. Therefore the above question remains philosophical, and cannot be settled by scientific arguments, i.e. experiments or calculations, as many researchers believe.