Nietzsche e l'astronomia del XIX secolo

The purpose of this thesis is to analyze the several celestial metaphors of Friedrich Nietzsche’s philosophy and to identify, beyond the purely aesthetical side, the scientific-astronomical view contained in them. For such a purpose it is necessary at first to examine the scientific notions of the German philosopher. We consider Nietzsche’s loans of books at University Library in Basel; his purchases, attested by the volumes present in his personal library (found today at the Studienzentrum of Herzogin Anna Amalia Bibliothek in Weimar); his personal correspondences, which contain Nietzsche’s book requests to friends; the receipts of his booksellers; and his personal encounters (First Part). In order to clarify the quantity and the quality of such readings, we analyze the studies of Pforta, Bonn and Leipzig, but we focus our attention particularly on two periods where Nietzsche’s interest centered on natural sciences: the 1870s (First Chapter) and the 1880s (Second Chapter). During the first period Nietzsche consulted several scientific journals and encyclopedias, borrowed mathematics, astronomy, meteorology and natural philosophy texts. After 1872, the year of the passage of the famous Comet Biela, he dedicated himself completely to the reading of books of popular astronomy. During the 1880s, after he took leave of the University of Basel, Nietzsche resumed his studies in natural philosophy, astronomy and meteorology. During this time, in Arcetri (Florence), he also met the astronomer Ernst Wilhelm Leberecht Tempel. Through the comparison of Nietzsche’s writings, his scientific readings, and the astronomical context of his time, it is possible to recognize the considerable influence that the latter exerted on his thoughts (Second Part). Therefore we trace some of Nietzsche’s best known thoughts back to precise astronomical references (First Chapter). Behind Nietzsche’s anti-anthropocentric and a-finalistic vision we do recognize a particular reworking of the Copernican heliocentrism. Behind the frequent solar metaphors we discover the nineteenth-century careful analysis of the spectroscopic studies conducted on the solar body. We interpret Nietzsche’s perspectivism in light of the important development of telescopes [Perspektive] during the nineteenth-century and considering the study of the alteration of the relative apparent position of the stars due to changes in the point of view of the observer (parallax). Furthermore we clarify Nietzsche’s conception of truth, exemplified by the figures of the death of God and of Zarathustra’s coming, by means of the nineteenth-century astronomical novelties: the measuring of the speed of light and of the distance of the stars, the introduction of the term “light-year” and the idea of the birth and death of the stars. Finally we discover, behind some of Nietzsche’s obscure expressions, erudite notions of astronomy (Second Chapter). Behind the figure of Thales in the lectures of Basel, we identify Nietzsche’s scrupulous study of the dating of the solar eclipse predicted by the pre-Platonic philosopher. In the assertions on the irregular form of the Milky Way (The Gay Science 109 and 322) we recognize the accurate astronomical analysis of our galaxy. We demonstrate the derivation of the poetic lunar metaphors present in Thus spoke Zarathustra from the specific physical characteristics of the moon. We recognize within the posthumous fragment 25 [518] dating back to spring 1884 punctilious references to the work The stars of the astronomer Father Pietro Angelo Secchi: spatial infinity, double stars and the motion of the whole solar system towards the constellation Hercules. Lastly we trace Nietzsche’s enigmatic expressions on sunspots back to the precise observational techniques of the solar body (projection) and to the periodicity of such spots. From the significant comparison between Nietzsche’s philosophy and nineteenth-century astronomy a new historical-scientific depth of Nietzsche’s intellectual profile emerges. We conclude, in fact, not only Nietzsche’s wide acquisitions of precise astronomical notions but also, and above all, his amazing ability to reuse those notions in an area different from the scientific one – philosophical speculation.