The aim of this paper is to analyze, from a philosophical perspective, the scientific robustness of the construct of psychopathy as measured by the Psychopathy Checklist Revised that was developed by Robert Hare (1991; 2003). The scientific robustness and validity of classifications are topics of many debates in philosophy of science and philosophy of psychiatry more specifically. The main problem consists in establishing whether scientific classifications reflect natural kinds where the concept of a natural kind refers to the existence of (...) some objective divisions in nature that do not depend exclusively on subjective judgments of the classifier. The construct of psychopathy is especially interesting since the diagnosis of psychopathy has substantial social consequences. In the light of the recent debates regarding the problem of natural kinds in philosophy of psychiatry, we advocate the following distinction between two types of scientific classifications: natural and practical kinds. Natural kinds refer to those categories that are united by common causal mechanisms or properties. Practical kinds refer to categories that fulfill some practical classificatory goals such as prediction. We argue that the construct of psychopathy can fulfill the role of a practical kind. In addition, we contend that our current scientific knowledge about psychopathy does not allow us to conclude that this category is a natural kind. (shrink)