The central questions of this research project are: i) What is the correlation between the adoption of Newtonian physics and the acceptance of determinism? ii) Should the question whether nature is deterministic be approached at a purely physical level or is it rather a philosophical issue, depending on philosophical ideas about physics?
I will try to give a new perspective on these questions through a historical study of the debate about determinism at the end of the nineteenth century. To understand the relation between physics and philosophy on the issue of determinism, it is useful to focus on a time when quantum mechanics had not yet entered and physics seemed to be deterministic. It is often assumed that determinism followed quite naturally from Newtonian physics and that it was therefore widely accepted by physicists before the introduction of quantum mechanics. But on the contrary, I will show that a number of nineteenth century physicists and philosophers doubted or rejected determinism in various ways.