Plato applied and adapted numbers to the form of that soul, and he stated that they enter, as it were, into its composition from the very fabric of the world, for which he held such a soul, as he is seen to have admitted. For he held that the distances that stretch from the earth up to the ninth, in fact, up to eighth heaven, according to him, are proportional to the numbers that he put in its shape, and he held that the whole world and its parts are musical, according to what I could understand about him, naturally suited and connected to one another in harmonious proportions and, for this reason, the soul of the world itself, which necessarily had to harmonize with and fit its body, was naturally united and somehow composed by similar connections, as I touched upon for you above when I spoke about the same and the other of it.

original latin

Hinc est quod, cum Plato credidisset nihil nisi suo simili delectari naturaliter, credidit animas nostras propter vehementissimas delectationes, quas habent animae nostrae in consonantiis simillimas esse ipsis, et propter hoc compositas esse ex consonantiis musicalibus, et inde etaim idem de anima mundi sensit, addens ipsi mundo velut musicam duplicem.

Multis autem viis et modis positio ista destruitur, et primum quia similia non solum fastidiunt, sed etiam contristant animas nostras.

Amplius, secundum hoc in solis numerabilibus et mensurabilibus esse delectatio animabus nostris. Quare in simplicibus et incorporalibus, scilicet, quantitatem non habentibus, nulla esset eis delectatio; quare nec in scientiis, nec in virtutibus, nec etiam in ipso creatore.

Amplius, quemadmodum animae nostrae tantis studiis consonantias exquirunt et instrumenta musicalia sibi fabricant amore suavitatis musicalis, sic et multo amplius anima illa consonantias istas exquiret et potissimum naturae suae et compositioni congruentissimas, ita ut si possibile esset, harmonicas melodias omnes coelos faceret resonare.

Iam autem declaravit Aristoteles musicalem sonum vel alium quemcumque ibi locum non habet, et propter hoc neque sonus, praesertim cum sonum emittat aer collisione hujusmodi compressus. Aerem vero in coelis esse impossibile est, cum locus ejus naturalis infra sphaeram lunae sit sub sphaera ignis.

Inconvenienter igitur collocata esset anima in parte superiori mundi corporei, in tanta scilicet naturae suae dissimilitudine ut cum ipsa composita sit ex numeris harmonicis, nihil harmoniae esset in illa regione sua.