I have been listening to some online lectures about medieval theology, and am currently working through the metaphysics of St. Thomas Aquinas as part of his proofs of the existence of God. These are very much introductory lectures, so I don’t expect the lecturer to go into great detail or deal with subtleties. However, as I listen to his examples and explanations, some possibly naive counter-examples from quantum mechanics come to mind. For instance, discussing the principle that nothing can change without being affected externally, I immediately thought of the spontaneous decay of atoms and even of particles (e.g., so-called proton decay).
As a very partial payment, I include Calvin’s opinion on metaphysics: