Tomasz Bigaj

The author presents and critically analyses different accounts of causal relation given by the main representants of Lvov-Warsaw School in philosophy. Although there are considerable differences between particular approaches to this problem, it is possible at least to distinguish the key questions, analysed and anwsered by these philosophers. Among them are such questions as: how to define „causal relation”, what are its formal features, what is the space-time localization of the effect and the cause, what are causal laws.

This book uses the formal semantics of counterfactual conditionals to analyze the problem of non-locality in quantum mechanics. Counterfactual conditionals enter the analysis of quantum entangled systems in that they enable us to precisely formulate the locality condition that purports to exclude the existence of causal interactions between spatially separated parts of a system. They also make it possible to speak consistently about alternative measuring settings, and to explicate what is meant by quantum property attributions. The book develops the possible-world semantics of quantum counterfactuals using David Lewis's famous approach as a starting point but modifying it significantly in order to achieve compatibility with the demands of the special theory of relativity as well as quantum mechanics. There have been several attempts to use counterfactuals semantics to strengthen Bell's theorem and its cognates such as the GHZ and Hardy theorems. These are critically evaluated in the book. Finally, a counterfactual reconstruction of the EPR argument and Bell's theorem is proposed that sheds a new light on their philosophical consequences regarding the relations between realism and local causation.

La notion mathématique de permutation d'indices dans la description de l'état peut recevoir différentes interprétations physiques. Deux interprétations principales analysées dans cet article sont l'échange des essences et l'échange des heccéités. On soutient ici qu'adopter l'approche essentialiste conduit à la conclusion selon laquelle les particules quantiques d'un même type sont parfois discernables par leurs propriétés, conclusion contraire à la sagesse conventionnelle. Seule l'interprétation alternative de l'heccéité primitive permet de soutenir la thèse de l'indiscernabilité.

The article deals with one particular problem created by the counterfactual analysis of causality à la Lewis, namely the context-sensitivity problem or, as I prefer to call it, the background condition problem. It appears that Lewis’ counterfactual definition of causality cannot distinguish between proper causes and mere causal conditions – i.e. factors necessary for the effect to occur, but commonly not seen as causally efficacious. The proposal is put forward to amend the Lewis definition with a condition, based on the notion of cotenability, which would eliminate the problem. It is shown that the corrected definition of causality leads to the transitivity of the causal relation. Possible objections to the proposed solution, involving the assumption of indeterminism and the preemption cases, are given a thorough consideration.