July 31

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  1669: Isaac Newton becomes known. Lucasian professor Isaac Barrow sent John Collins a manuscript of Newton's De analysi and thereby Newton's anonymity began to dissolve. Although this manuscript was not published until 1704, it led to Newton's appointment as Lucasian professor on 29 October 1669.

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  1704: Mathematician and physicist Gabriel Cramer born. He will publish Cramer's rule, giving a general formula for the solution for any unknown in a linear equation system having a unique solution, in terms of determinants implied by the system.

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  1784: Philosopher, art critic, and writer Denis Diderot dies. He was a prominent figure during the Enlightenment, serving as co-founder, chief editor, and contributor to the Encyclopédie along with Jean le Rond d'Alembert.

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  1926: Philosopher, mathematician, and computer scientist Hilary Putnam born. He will argue for the reality of mathematical entities, later espousing the view that mathematics is not purely logical, but "quasi-empirical".