**Hi Max,**

**Have you ever drawn a graph? Very mathematical of you. The idea came from a Christian bishop who was another in the series of pioneers of science who were also people of faith. I have lots more to show you. Cheers.**

**Nicole Oresme** 1320-1382, France

also known as **Nicolas d’Oresme**, was a significant philosopher of the later Middle Ages. He wrote influential works on economics, mathematics, physics, astrology and astronomy, philosophy, and theology; was Bishop of Lisieux, a translator, a counselor of King Charles V of France, and probably one of the most original thinkers of the 14th century.[2]

In his *Livre du ciel et du monde* Oresme discussed a range of evidence for and against the daily rotation of the Earth on its axis.[6] In his mathematical work, Oresme developed the notion of incommensurate fractions, fractions that could not be expressed as powers of one another, and made probabilistic, statistical arguments as to their relative frequency.[11]

Oresme’s most important contributions to mathematics are contained in *Tractatus de configurationibus qualitatum et motuum*. In a quality, or accidental form, such as heat, he distinguished the *intensio* (the degree of heat at each point) and the *extensio* (as the length of the heated rod). For the sake of clarity, Oresme conceived the idea of visualizing these concepts by plane figures, approaching what we would now call rectangular co-ordinates.. Oresme proposed that the geometrical form of such a figure could be regarded as corresponding to a characteristics of the quality itself.

He extended this doctrine to figures of three dimensions. He considered this analysis applicable to many different qualities such as hotness, whiteness, and sweetness. Significantly for later developments in calculus, Oresme applied this concept to the analysis of local motion where the *latitudo* or intensity represented the speed, the *longitudo* represented the time, and the area of the figure represented the distance travelled.[19]; thus Oresme manages to anticipate Galileo´s discovery.[20][21]

Significantly, Oresme developed the first proof of the divergence of the harmonic series, something that was only replicated in later centuries by the Bernoulli brothers. He was the first mathematician to prove this fact, and (after his proof was lost) it was not re-proved until the 17th century.[22]He also worked on fractional powers, and the notion of probability over infinite sequences, ideas which would not be further developed for the next three and five centuries, respectively.[11]

In his *Treatise on the origin, nature, law, and alterations of money*, one of the earliest manuscripts devoted to an economic matter, Oresme brings an interesting insight on the medieval conception of money.