Essentialist theories are based on notions of necessity and essentiality. Kinds and Quasi-Kinds can be defined in terms of these notions. Aristotle's essentialism asserts that Kinds are unions of Quasi-Kinds, Kinds that can overlap are necessarily included in a common Kind, and Kinds partition into sub-Kinds. Truth-conditions for the apodeictic propositions of Aristotle's modal syllogistic are stated in terms of necessity and essentiality, but independent of theses -. While the basic insights motivating Patterson's and Nortmann's interpretations of modal syllogistic are (...) sound, nonetheless there are significant mistakes in the detail. Given -, truth-conditions for apodeictic propositions can be stated in terms of essentiality, but independently of the notion of necessity, thus confirming Johnson's interpretation. (shrink)

Aristotle's modal syllogistic has been an object of study ever since the time of Theophrastus; but these studies have been somewhat desultory. Remarkably, in the 1990s several new lines of research have appeared, with series of original publications by Fred Johnson, Richard Patterson and Ulrich Nortmann. Johnson presented for the first time a formal semantics adequate to a de re reading of the apodeictic syllogistic; this was based on a simple intuition linking the modal syllogistic to Aristotelian metaphysics. Nortmann developed (...) an ingenious de dicto analysis. Patterson articulated the links between the modal syllogistic and the metaphysics, using an analysis which strictly speaking is neither de re nor de dicto. My own studies in this field date from 1976, when my colleague Peter Roeper and I jointly wrote a paper "Aristotle's apodeictic syllogisms" for the XXIInd History of Logic Conference in Krakow. This paper contained the disjunctive reading of particular affirmative apodeictic propositions, which I still favour. Nonetheless, I did not consider that paper's results decisive or comprehensive enough to publish, and my 1981 book The Syllogism contained no treatment of the modal syllogism. The paper's ideas lay dormant till 1989, when I read Johnson's and Patterson's initial articles. I began publishing on the topic in 1991. Gradually my thoughts acquired a certain comprehensiveness and systematicity, till in 1993 I was able to take a semester's sabbatical to write up a draft of this book. (shrink)

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)