Abstract
The notion of 'natural kinds' has been central to contemporary discussions of metaphysics and philosophy of science. In recent years, essentialism has been the dominant account of natural kinds among philosophers, but the essentialist view has encountered resistance. Informed by detailed examination of classification in the natural and social sciences, Prof. Muhammad Ali Khalidi argues against essentialism and for a naturalist account of natural kinds. By looking at case studies drawn from diverse scientific disciplines, from fluid mechanics to virology and polymer science to psychiatry, the author argues that natural kinds are nodes in causal networks. On the basis of this account, he maintains that there can be natural kinds in the social sciences as well as the natural sciences.