Early modern astrolabe from Danti, Egnazio, Trattato dell' vso et della fabbrica dell' astrolabio: con l' aggivnta del planisferio del roias, 1569.
"Utilitas astronomiae": Renaissance Reflections on the Practical Dimension of Astronomy
This paper is an assessment of Renaissance scholars’ views of the practical embedment of astronomy. In order to tackle this issue, I deem it expedient to address the widespread "scientific topos" of the utilitas astronomiae (astronomy’s utility) as it arises from several early modern works of astronomy and on astronomy. Historians of science have often neglected this issue to the advantage of its rhetorical counterpart, namely the dignitas astronomiae (astronomy’s dignity), which was the reflection on the excellence of astronomy descending from interdisciplinary connections with philosophy, ethics and theology. By contrast, the emphasis on the utilitas pointed to the practical advantages deriving from the knowledge about the heavens. According to sources, the practical realms benefiting from astronomy ranged from navigation and agriculture, to medicine and civil affairs, for instance calendar computation and the establishment of religious festivities.
Variations of the theme of the utilitas astronomiae can be found in many works, by very different authors that I would like to review: the Averroist philosopher Girolamo Fracastoro in his Homocentrica (Venice, 1538), the Wittenberg ephemerist Erasmus Reinhold in the dedicatory letter of his commented edition of Ptolemy’s Almagest, Book One (Wittenberg, 1549), the renowned Jesuit mathematician Christopher Clavius in the preface to his commented edition of Sacrobosco’s De sphaera, and the Scottish mathematician Duncan Liddel in a manuscript eulogy of mathematics which is the transcription of a talk delivered at Helmstedt, Germany, in 1591. As an extreme case, I will discuss the reduction of "dignity" to "utility" by the Calvinist lecteur royale Pierre de la Ramée in his Scholae mathematicae (Basel, 1569).