Cosmologia e armonia in Kepler e Mersenne: Contrappunto a due voci sul tema dell'Harmonice mundi (review)

Providing a veritable mine of primary source citations, Fabbri explains how the cosmological agendas of Kepler and Mersenne exemplify a moment in which astronomy and music, "two sister sciences" (6) of the early modern era, experienced revolutionary change. As Fabbri claims, not only has the theme of harmonice mundi been underappreciated as a too-distant factor in the formulation of modern science, but the ways in which the notion of a "polyphonic cosmos" (6) actually developed from the emergence of modern science have not sufficiently been shown. The harmonice mundi theme retained a "primary role" (245) throughout a critical stage, in which discoveries occurring in astronomy, optics, mechanics, and acoustical physics — elements all intimately intertwined in the harmonice mundi theme — irreversibly altered the foundations of general knowledge. Fabbri aims not to overemphasize the significance of modern science in this upheaval, however, and criticizes those historians who have interpreted in "extremely reductive" (7), mechanistic terms Mersenne's Traité de l'Harmonie Universelle, thereby missing the profound influence exercised by Kepler's more comprehensive, less seemingly modern notion of harmony in his Harmonice mundi. Despite the differences Fabbri points out between Kepler and Mersenne, the "parallel progression" (5) of astronomy and music illustrated by each of their "cosmological programs" (245) reveals the extent to which the harmonice mundi theme contributed to, encompassed, and grew out of the many changes undergone in early modern science.

That Kepler and Mersenne conceived of the world in harmonic terms, Fabbri suggests, can be largely attributed to their shared theological conviction in geometry as "coeternal and coessential to the Creator" (11). "The geometrical archetypes present to the divine mind of the supreme Musician" (11, 221) were thus seen by Kepler and Mersenne as tools essential for the act of Creation and for its subsequent human comprehension. Perhaps the clearest sign of the central importance of geometry for both, Fabbri claims, is the use they made of the sphere as the archetypal embodiment of the Trinitarian nature of the cosmos (the center, surface, and intervening equidistant space), in which the Holy Trinity was represented as the physical cosmos. Fabbri's emphasis on the archetypal significance for Kepler of the sphere and of geometry more generally echoes the earlier assertions of Alexandre Koyré (The Astronomical Revolution [1961], 119, 121). Her description of the analogical nature of Mersenne's notion of harmony, distinct from that of Kepler in that geometric forms functioned more in a "persuasive discourse" without reference to any "immanent metaphysical sense," largely reiterates the claims of Fernand Hallyn (The Poetic Structure of the World [1990], 226). Fabbri moves beyond these and other sources, however, in her investigation of the living, or animistic, side of each thinker's conception of the harmonice mundi theme. And, in terms of the theological/archetypal side of early modern music theory, she improves upon the argument of D. P. Walker ("Kepler's Celestial Music" [1967], 232) by explaining exactly why Kepler considered the sense of hearing to be the unrivaled "tribunal of common sense" (47).

Two points in Fabbri's argument merit mention. First, her claim that Kepler "abandoned" (27, 192) his polyhedral model of the planets in favor of a polyphonic scheme is too extreme: although the more accurate astronomical observations of Tycho Brahe led Kepler to modify his original theory, it remained "the scaffolding from which he would later construct the detailed harmonic theory in the Harmonice mundi" (Bruce Stephenson, The Music of the Heavens [1994], 89). Second, Fabbri's dismissal of Kepler's astrology as something of "marginal importance" (187) misses the magnitude of one of the central-most components in Kepler's harmonic conception of the cosmos: in addition to the many relations in Kepler's thought "between the ratios of string lengths that define musical consonances and the divisions of the...