There have been many attempts to determine what makes a natural kind real, chief among them is the criterion according to which natural kinds must be mind-independent. But it is difficult to specify this criterion: many supposed natural kinds have an element of mind-dependence. I will argue that the mind-independence criterion is nevertheless a good one, if correctly understood: the mind-independence criterion concerns the unification principles for natural kinds. Unification principles determine how natural kinds unify their properties, and only those (...) natural kinds that have a mind-independent unification principle should be considered real. (shrink)

Categoricalism is a doctrine about properties according to which the dispositional aspects of properties are not essential to them. In opposition to categoricalism, dispositionalism holds that the dispositional aspects of properties are essential to them. In this article, I shall construct a new version of categoricalism that should be favoured over the other existing versions: Semi-Necessitarian Categoricalism. In Section 2 I shall elaborate on the distinction between categoricalism and dispositionalism and single out different ‘shades’ of both doctrines. I shall also (...) illustrate the main advantages and problems that characterize categoricalism. In Section 3 I shall introduce Necessitarian Categoricalism—as it has been recently developed by Alexander Kelly and Deborah Smith, among others. Even if Necessitarian Categoricalism solves the aforementioned problems of categoricalism, it also loses its main advantages. In Section 4 I shall refine this version of Necessitarian Categoricalism, thus developing Semi-Necessitarian Categoricalism. In Section 5 I shall face some objections. Finally, in Section 6, I shall briefly draw some conclusions and compare my account with other accounts. (shrink)

Is it possible to get by with just one ontological category? We evaluate L.A. Paul's attempt to do so: the mereological bundle theory. The upshot is that Paul's attempt to construct a one category ontology may be challenged with some of her own arguments. In the positive part of the paper we outline a two category ontology with property universals and kind universals. We will also examine Paul's arguments against a version of universal bundle theory that takes spatiotemporal co-location instead (...) of compresence or coinstantiation as the feature by which we can identify genuine bundles. We compare this novel theory, bundle theory with kinds, and Paul's mereological bundle theory and apply them to a case study concerning entangled fermions and co-located bosons. (shrink)