This work reconstructs some key moments of the debate on the concept of "human race" that took place in the late eighteenth century among Kant, Forster and Herder. It aims to show, first, that this controversy was defined by the need to adapt the natural-historical tools inherited from the emergence of a conception of irreversible temporality. Secondly, it analyses Kant´s position regarding the epistemic problems generated by the progressive temporization of natural phenomena. Based on this analysis, it is shown that the introduction of regulative principles and the Kantian turn toward subjectivity tended to support the validity of the classic understanding of natural-organic forms, and thus, to guarantee the systematic character of natural order in a context in which historical and natural transformations could no longer be conceived under the classic model of temporal reversibility.
Kant; Forster; Herder; Human race; Natural History; Temporality