 In considering the general interconnection of sciences, Mersenne granted music an almost architectonic function. All the sciences borrow something from each other. As manifested in the encyclopedic character of the Harmonie Universelle, music was for Mersenne as the connecting principle of the various disciplines, allowing for their exposition. A thorough investigation of musical properties requires forays into theology, moral philosophy (the passions of the soul), optics, arithmetic and geometry, and of course mechanics as sounds are motions of the air, that have to be accounted for in a mechanical way. Conversely, and at a deeper level, music may be seen as a total science, theoretically capable of representing the proportions that exist between all parts of the mechanical universe: