Bk. 1, ch. 4. Translated by Robert B. Burke, in: Edward Grant (1974) Source Book in Medieval Science. Harvard University Press. p. 93
Opus Majus, c. 1267
“An ancient writer said that arithmetic and geometry are the wings of mathematics; I believe one can say without speaking metaphorically that these two sciences are the foundation and essence of all the sciences which deal with quantity. Not only are they the foundation, they are also, as it were, the capstones; for, whenever a result has been arrived at, in order to use that result, it is necessary to translate it into numbers or into lines; to translate it into numbers requires the aid of arithmetic, to translate it into lines necessitates the use of geometry.”
Dans Les Leçons Élémentaires sur les Mathématiques (1795) Leçon cinquiéme, Tr. McCormack, cited in Moritz, Memorabilia mathematica or, The philomath's quotation-book (1914) Ch. 15 Arithmetic, p. 261. https://archive.org/stream/memorabiliamathe00moriiala#page/260/mode/2up
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Joseph Louis Lagrange 6
Italian mathematician and mathematical physicist 1736–1813Related quotes
Source: Recreations in Mathematics and Natural Philosophy, (1803), p. 2
Source: Mathematical Lectures (1734), p. 44
Nicomachus of Gerasa: Introduction to Arithmetic (1926)
“It is not of the essence of mathematics to be conversant with the ideas of number and quantity.”
Source: 1850s, An Investigation of the Laws of Thought (1854), p. 12; Cited in: Alexander Bain (1870) Logic, p. 191
Interview with Harvard Business Review, https://hbr.org/ideacast/2017/08/when-startups-scrapped-the-business-plan.html.3 August 2017