Alex Blum

This paper studies the notion of virtuality in the Bohr-Kramers-Slater theory of 1924. We situate the virtual entities of BKS within the tradition of the correspondence principle and the radiation theory of the Bohr model. We show how, in this context, virtual oscillators emerged as classical substitute radiators and were used to describe the otherwise elusive quantum transitions. They played an effective role in the quantum theory of radiation while remaining categorically distinct and ontologically separated from the quantum world of the Bohr model. The notion of virtuality thus differs markedly from its counterpart in quantum mechanics or QFT.

We suggest that the classical version of the consequence argument contending that freedom and determinism are incompatible subtly misstates the core intuition, which is that if a true conditional and a true antecedent are jointly beyond our control, then so is the consequent. We show however that the improved version no less than the classical implies fatalism.Interestingly, the reasoning, that yields fatalism, undermines a direct argument for the soundness of the improved version. But if fatalism is sound, then trivially, so is the new version. We shall however argue that the new version cannot be sound. A weaker version is proved sound but its domain of application excludes the most intuitive paradigm cases.We share van Inwagen's thought that his “‘N’is a very interesting operator” and debate some of its features. Our results, if sound, suggest that the consequence argument in terms of ensurable and non‐ensurable truth may not be the right way to approach issues of determinism and freedom.