Natural Kinds and Projectible Predicates

The focus of this article is on the pragmatic presuppositions involved in the use of general terms in inductive practices. The main thesis is that the problem of characterizing the assumptions underlying the projection of predicates in inductive practices and the ones underlying the classification of crtain general terms as «natural kind terms» coincide to a good extent. The reason for this, it is argued, is that both classifications, «projectibility» and «natural kind term», are attempts to answer to the same semantico-epistemological phenomenon, viz. underdertermination. It is proposed a «deflationary» reading of the so-called «theory of direct reference» as to enable an evaluation of its contribution to epistemological problems associated with this kind of phenomena, as well as it is argued that a purely de facto account of projectibility is not viable. The resulting hypothesis is that the conception of «natural kind terms» is only interesting insofar as they are seen as a kind of projectible general terms and thus as parts of classifications used in natural science, more generally, in inductive practices, and that this is a perspective that makes undue metaphysical readings avoidable.