Kepler's prevailing musical model is in fact more homophonic-that is, a single melody supported by chords-than polyphonic. He notes that the planets mimic the distinctive four parts of a harmonized chorale: a wide-ranging treble and tenor, stable alto line, and leaping bass line. Also, if Kepler's aim had been to prove the polyphonic structure of the universe, he surely would have been less sanguine about his discovery that the planets wailed rather than sang. Perhaps most importantly, Kepler's approach was empirical, not symbolic: he had no time for those like Robert Fludd who tried to force the cosmos into a symbolic scheme. Thus, Pesic's characterization of Kepler's Harmony of the World as "one of the most extraordinary defenses of polyphony ever written" (p. 145) is not convincing, except perhaps in the very broad sense that the universe contains many objects in simultaneous motion, some of which are in harmonious relationships, as demonstrated by Kepler's Third Law. Pesic extends his study of polyphony "far beyond the traditional limits of music" (p. 209) in order to accommodate not only twentieth-century polyphonic compositions but also non-Western polyphony. In Chapter 13, he discusses Max Weber's view of music within a process of social rationalization. It is worth noting that if Pesic had adopted Weber's definition of polyphony, "several voices of equal standing run side by side, harmonically linked" (p. 238), he would have had an easier time connecting polyphony to developments in early modern science. Although Weber's writings served to promulgate the superiority and uniqueness of western rationalized society, his definition of polyphony at least provides a clear and focused category for comparison and study. Was it simply the feature of "many-voicedness" that made music such a powerful analogy for the natural sciences, or was there something about "Western" polyphony that helped foster "Western" science? Pesic is troubled that even in neuroscience, researchers seem to be falling back onto concepts from "traditional polyphony" such as melody or orchestral section leaders. He suggests that his broader field of view will provide more valuable polyphonic models for the sciences. It remains to be seen whether the hundred wind-up metronomes of Ligeti's Poème Symphonique will prove as rich a source of insights for neuroscience as a "traditional" symphonic poem. Nonetheless, Polyphonic Minds: Music of the Hemispheres is a welcome reminder of music's enduring significance to the history of the sciences.

In this paper we discuss the notion of Arabic literary works which, to the best of our knowledge, have been lost over the course of history. We examine factors contributing to the likelihood of transmission, address current interdisciplinary debates, and discuss digital tools applied to estimating the loss of literary heritage or to retrieving information on lost works. Our aim is to highlight the potential that bio-bibliographical works hold for the study of lost texts and manuscripts. Three possibilities are presented for studying lost books mentioned in Ibn Abī Uṣaybiʿa's History of Physicians (ʿUyūn al-anbā ̉ fī ṭabaqāt al-aṭibbā ), and these include the identification of lost works in bio-bibliografical reference works, the encoding of attestations for manuscripts written by the authors themselves, and the reconstruction of scholarly networks which contributed to a certain lost work. The examples discussed demonstrate the advantages prosopographical networks can offer if they include works and manuscripts. Therefore, we put a particular focus on the use of machine-readable assertions which involves encoding the claims and statements from primary sources in a format that enables computer systems to process and analyse them.

No abstract