Search Loci: Convergence:
You treat world history as a mathematician does mathematics, in which nothing but laws and formulae exist, no reality, no good and evil, no time, no yesterday, no tomorrow, nothing but an eternal, shallow, mathematical present.
The Glass Bead Game, 1943.
Benedetto da Firenze's Trattato d'arismetriche
Benedetto da Firenze (1429 – 1479) was a respected Florentine maestro d’abaco. Here, on page 114 of his unpublished manuscript Trattato d’arismetricha (ca 1460), a work on mercantile arithmetic, is a discussion of regula del chataina, the chain rule, used to compute exchange rates.