This study engages a network of music, myth, and metaphysics within late-ancient and twelfth-century music theory and cosmology. It traces the development, expansion, and demise of a (natural-)philosophical harmonic speculation that stems largely from an a priori commitment to a harmonic cosmology with its deepest roots in Plato’s Timaeus. It argues that music theory not only allowed twelfth-century thinkers to conceptualize the fabric of the universe, but it also provided a hermeneutic tool for interpreting the ancient and late-ancient texts that offered detailed theories of the world’s construction. The twin goals of this study are thus philosophical and musicological: firstly and philosophically, to analyze and re-assert the importance of musical speculation in the writings of the self-styled physici, who probed the physical world and its metaphysical foundations during the ‘Twelfth-Century Renaissance’; secondly and musicologically, to document the sources and scope of this musical speculation and to situate it within the larger tradition of ‘speculative music theory.’ The first part of the thesis (chapters one and two) disentangles the knotty question of sources for and connections between the late-ancient texts (by Calcidius, Macrobius, and Boethius) that form the background of twelfth-century thought, and it sketches the proper domain of musical thought by tracing the expansion of music’s role in quadrivial and natural-philosophical contexts from late-ancient encyclopedism though various twelfth-century divisiones scientiae. The second part of the thesis (chapters three through five) assembles and analyzes the direct evidence for twelfth-century harmonic theory. These chapters, heuristically organized around the Boethian tripartition of music, present an anagogic ascent per aspera ad astra. Chapter three (musica instrumentalis) highlights the occasional and perhaps surprising employ of practical, technical music theory in cosmological contexts, and focuses on the epistemological foundations of hearing and the ontological status granted to the sonorous ‘objects’ of hearing. Chapter four (musica humana) targets the anthropological, psychological, and ethical implications of musical relations in and between body and soul. Finally, chapter five (musica mundana) outlines the cosmological framework, the anima mundi in particular, that underpins the concordant machinations of the machina mundi in all its manifestations.

This study engages a network of music, myth, and metaphysics within late-ancient and twelfth-century music theory and cosmology. It traces the development, expansion, and demise of a (natural-)philosophical harmonic speculation that stems largely from an a priori commitment to a harmonic cosmology with its deepest roots in Plato’s Timaeus. It argues that music theory not only allowed twelfth-century thinkers to conceptualize the fabric of the universe, but it also provided a hermeneutic tool for interpreting the ancient and late-ancient texts that offered detailed theories of the world’s construction. The twin goals of this study are thus philosophical and musicological: firstly and philosophically, to analyze and re-assert the importance of musical speculation in the writings of the self-styled physici, who probed the physical world and its metaphysical foundations during the ‘Twelfth-Century Renaissance’; secondly and musicologically, to document the sources and scope of this musical speculation and to situate it within the larger tradition of ‘speculative music theory.’ The first part of the thesis (chapters one and two) disentangles the knotty question of sources for and connections between the late-ancient texts (by Calcidius, Macrobius, and Boethius) that form the background of twelfth-century thought, and it sketches the proper domain of musical thought by tracing the expansion of music’s role in quadrivial and natural-philosophical contexts from late-ancient encyclopedism though various twelfth-century divisiones scientiae. The second part of the thesis (chapters three through five) assembles and analyzes the direct evidence for twelfth-century harmonic theory. These chapters, heuristically organized around the Boethian tripartition of music, present an anagogic ascent per aspera ad astra. Chapter three (musica instrumentalis) highlights the occasional and perhaps surprising employ of practical, technical music theory in cosmological contexts, and focuses on the epistemological foundations of hearing and the ontological status granted to the sonorous ‘objects’ of hearing. Chapter four (musica humana) targets the anthropological, psychological, and ethical implications of musical relations in and between body and soul. Finally, chapter five (musica mundana) outlines the cosmological framework, the anima mundi in particular, that underpins the concordant machinations of the machina mundi in all its manifestations.

This study offers a reinterpretation of the direct tradition of medieval Platonism on the basis of new evidence from the Meno and the Phaedo translated into Latin by Henry Aristippus between 1154 and 1160. In particular, it provides an edition of interlinear and marginal annotations and glosses of the Meno and the Phaedo: the manuscript tradition is particularly useful for understanding which aspects of these two Platonic dialogues were particularly studied during the Middle Ages, as it preserves the considerations of various readers on Platonic philosophy. In the most fortunate cases, it is precisely the manuscript tradition that offers new perspectives that can be used to redesign the networks of reception of the two Platonic texts examined in this study in the centuries following their translation, with particular reference to the 13th and 14th centuries. The research was carried out on unpublished material and manuscript testimonies, with the help of two strategies. First, the medieval sources were submetted to a doxographic analysis, through a bottom-up approach consisting in the identification of the terms ‘Plato’, ‘Meno’, ‘Phaedo’ (or ‘Fedrone’ according to medieval usage). This allowed to understand in which contexts and in relation to which themes the references to the three terms appeared and to provide a list of authors who, between the 13th and the 14th century, had the opportunity to read the Meno and/or the Phaedo in Henry Aristippus’ translation. The second strategy, which we could perhaps describe as ‘inside-out’, was applied in the editing phase of the interlinear and marginal annotations and glosses of the two translations. As an especially important paratextual element, the ‘marginal’ writing proves to be particularly useful for deriving the constituent elements of the two dialogues (inside) that were commented, re-written, re-elaborated and interpreted in the margins of the two texts (outside). By employing both strategies, it is possible to reveal the core concepts of Platonic philosophy that, to a greater or lesser extent, caught the attention of medieval readers of the Latin Meno and the Phaedo.