267 p.The Anthropocene is a polyvocal term referring to a wide range of concepts, some of which remain under construction. This dissertation does not refer to the usual meaning of the word, as adopted by the academic circles of social sciences and humanities, but rather focuses on its original signification within natural sciences, namely: (i) as a change of state in the Earth System and (ii) as a potentially new Geological Time Unit. In contrast to the ideal of value-free objectivity implied by the dominant scientific discourse, the aim of this research is to comprehend how both conceptions are underpinned by a multitude of values, both explicitly and subtly.A central theme of the text is an examination of the Anthropocene Working Group (AWG), which, as of 2009, has been responsible for gathering empirical evidence in support of an eventual formalization of the Anthropocene in the International Chronostratigraphic Chart. First, it is shown that the conformation of the group was explicitly guided by ¿utility¿, a common epistemic value in the stratigraphic community. In this case, however, it has since been transmuted into a social, ecological and legal value. This axiological shift is discernible after revealing the sociohistorical linkage between the group and the recently constituted Earth System Science (ESS), wherein the term was first conceptualized and popularized from 2000 onwards.Understanding the underlying axiology of the Anthropocene, therefore, requires a reconstruction of its intellectual history. Second, alternative to the internalist, teleological and positivist historiography prevailing in scientific literature, it is demonstrated how the Anthropocene was an instance conditioned by the historical context of the second half of the 20th century, where the dangers of global change, modern ecologism, the internationalization of science, space exploration and advancements in computational technologies gave rise to a new object of study and intervention: the Earth System.The history of the Anthropocene conceptualization is then contrasted with a historical alternative derived from the 19th century. In 1873, the Italian geologist Antonio Stoppani first conceived of a geological era he denominated as ¿Anthropozoic¿¿this proposal subsequently being forgotten in the mid-twentieth century. The comparative reconsideration of his work reveals the implicit role of contextual values in both scientific formulations, entailing a set of background assumptions which need to be foreseen and taken into account. The entire process carried out in this dissertation can thus be understood through the framework I have formulated herein of ¿Historical Axiology¿: an integrative approach between philosophy and history of science, where the former provides the abstract vehicle of the historical narrative, while the latter allows for a situated reflection on the values present in our contemporary concerns
