Essentialism is, on the one hand, anchored with considerable firmness in a common sense picture of the world. On the other hand, it was dismissed for logico-philosophical reasons by a scientifically minded theorist like Quine. ``New essentialists'' like Kripke did engage in very profitable theorizing on an essentialist basis, but made no significant effort to investigate the prospects of imparting to an essentialist metaphysics a solid foundation within a scientific world view. These foundational prospects are the concern of the article. (...) – The investigation is guided by two ideas which are elaborated within a proof theoretical framework in the course of the article. First, being an essential F (where ``F'' represents a predicate) is linked with a lifelong possession of the property signified by ``F'' (but there is something more in it). Second, a special kind of necessity is involved in (true) predications of essential F-ness; it should be capable, like possibly all kinds of necessity, of being spelt out, in the final analysis, in terms of the provability of appropriate propositions in appropriate theoretical systems. In outlining the relevant axiomatic bases, the article draws on an early paper by E. Hirsch on individuation and essence. (shrink)

A world without individual entities? An advice to not to extract immediate ontological consequences from quantum theory. Should we assume a world without individual entities? I pledge not to extract immediate ontological consequences from quantum theory. My intention is to focus on the complexity of ontological concepts commonly associated with quantum theory. Using as an example the compatibility of EPR correlations with the existence of individual entities, it is shown that an absolute rejection of an ontological category, based on some (...) aspects of the formalism of quantum theory, does not seem reasonable. A consequence of this argument is that the common sense view – the world is composed of individual entities – can be maintained, despite of the particularities of quantum mechanics. (shrink)