Scientific Essentialism defends the view that the fundamental laws of nature depend on the essential properties of the things on which they are said to operate, and are therefore not independent of them. These laws are not imposed upon the world by God, the forces of nature or anything else, but rather are immanent in the world. Ellis argues that ours is a dynamic world consisting of more or less transient objects which are constantly interacting with each other, and whose identities depend on their roles in these processes. Natural objects must behave as they do, because to do otherwise would be contrary to their natures. The laws of nature are, therefore, metaphysically necessary, and consequently, there are necessary connections between events. Brian Ellis calls for the rejection of the theory of Humean Supervenience and an implementation of a new kind of realism in philosophical analysis. – Contents : Preface; Introduction; – Part I. Concepts: 1. Concepts of scientific essentialism; – Part II. Ontology: 2. Natural kinds; 3. Powers and dispositions; – Part III. Scientific Explanation: 4. Realism and essentialism in science; 5. Essentialism in the social sciences; – Part IV. Laws of Nature: 6. Theories of laws of nature; 7. Natural necessity; – Part V. The New Essentialism: 8. The essentialist program. – Bibliography; Index.