 This edifying use of mathematics is perhaps the hallmark of Mersenne’s writings. It is still very much present in later publications (such as the Harmonie Universelle). The minim is literally fascinated by the almost magical properties of numbers and geometrical figures, where the most surprising and complicated objects and properties are generated from the simplest principles. This gives him a general analogy for religious truths. There are “thousands of things in the mysteries of faith” that are “incomprehensible to the pagan and to a peripatetic philosopher”, but that may be made understood by a “Christian Euclid” (un Euclide chrétien) : Mathematics makes the relation of the infinite to the finite sensible, showing how an infinite motion can be made in a finite space. It can thus “explain” the union of the two natures in the same divine person. Although the mathematical point is the humblest object, “the minim of geometry” (HU III: Livre de l’Utilité de l’Harmonie, 16), it is in a sense the closest to God itself. Both are simple, without parts. The point engenders the line and together with the line, the surfaces, and with lines and surfaces the bodies. This gives us an insight on how God engenders the son, the son and God together, the holy spirit, and then all together the universe. Unity contains all numbers eminently, as God contains all created acts and all creatures, etc (ibid. 16–17). Mersenne also likes to suggest mathematical analogies illustrating, or symbolizing moral virtues. Thus, as the height of a triangle is measured by a perpendicular line elevated from the basis, the goodness of our actions is measured by the righteousness of our intention (“la droite intention”, VS I: 12). Mixed mathematics, optics, music and mechanics are also mobilized in the moral use of mathematics. For example: