There is a perennial philosophical dream of a certain natural order for the natural kinds. The name of this dream is ‘the hierarchy requirement’. According to this postulate, proper natural kinds form a taxonomy which is both unique and traditional. Here I demonstrate that complex scientific objects exist: objects which generate different systems of scientific classification, produce myriad legitimate alternatives amongst the nonetheless still natural kinds, and make the hierarchical dream impossible to realize, except at absurdly great cost. Philosophical hopes (...) for a certain order in nature cannot be fulfilled. Natural kinds crosscut one another, ubiquitously so, and this crosscutting spells the end of the hierarchical dream. (shrink)

In 2013, Bennett proposed a mereological theory in which the parthood relation is defined on the basis of two primitive relations: a is a part of b iff a fills a slot owned by b. However, this theory has issues counting how many parts an entity has. We explore the various counting problems and propose a new theory to solve them. Keeping the core idea of Bennett’s slots, this theory introduces mereological relations between slots. This theory enables us to solve (...) all known counting problems and to go beyond the limits of Bennett’s theory by theorising expected features of mereological theories: supplementation principles and mereological sum and fusion. The theory is illustrated on ontological issues on the nature of structural universals and informational entities. (shrink)

The place of chemistry in the metaphysics of science may be viewed as peripheral compared to physics and biology. However, a metaphysics of science that disregards chemistry would be incomplete and ill-informed. This Element establishes this claim by showing how key metaphysical issues are informed by drawing on chemistry. Five metaphysical topics are investigated: natural kinds, scientific realism, reduction, laws and causation. These topics are spelled out from the perspective of ten chemical case studies, each of which illuminates the novel (...) ways that metaphysics of science can be informed by chemistry. (shrink)