Hermann Grassmann (1809–1877) German polymath, linguist and mathematician
Forward, as quoted by Mario Livio, Is God a Mathematician? (2009)
Ausdehnungslehre (1844)
Robert Chambers, Chambers's Information for the People (1875) Vol. 2 https://books.google.com/books?id=vNpTAAAAYAAJ
Hermann Grassmann (1809–1877) German polymath, linguist and mathematician
Forward, as quoted by Mario Livio, Is God a Mathematician? (2009)
Ausdehnungslehre (1844)
“Geometry, to which I have devoted my life, is honoured with the title of the Key of Sciences”
Benjamin Peirce (1809–1880) American mathematician
Ben Yamen's Song of Geometry (1853)
Context: Geometry, to which I have devoted my life, is honoured with the title of the Key of Sciences; but it is the Key of an ever open door which refuses to be shut, and through which the whole world is crowding, to make free, in unrestrained license, with the precious treasures within, thoughtless both of lock and key, of the door itself, and even of Science, to which it owes such boundless possessions, the New World included. The door is wide open and all may enter, but all do not enter with equal thoughtlessness. There are a few who wonder, as they approach, at the exhaustless wealth, as the sacred shepherd wondered at the burning bush of Horeb, which was ever burning and never consumed. Casting their shoes from off their feet and the world's iron-shod doubts from their understanding, these children of the faithful take their first step upon the holy ground with reverential awe, and advance almost with timidity, fearful, as the signs of Deity break upon them, lest they be brought face to face with the Almighty.
Joseph Louis Lagrange (1736–1813) Italian mathematician and mathematical physicist
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
Nicomachus (60–120) Ancient Greek mathematician
Book I, Chapter III, p.184
Nicomachus of Gerasa: Introduction to Arithmetic (1926)
W. V. D. Hodge (1903–1975) British mathematician
W. V. D. Hodge, Changing Views of Geometry. Presidential Address to the Mathematical Association, 14th April, 1955, The Mathematical Gazette 39 (329) (1955), 177-183.
Henri Poincaré book Science and Hypothesis
Source: Science and Hypothesis (1901), Ch. IV: Space and Geometry, Conclusions (1905) Tr. https://books.google.com/books?id=5nQSAAAAYAAJ George Bruce Halstead
Howard P. Robertson (1903–1961) American mathematician and physicist
Geometry as a Branch of Physics (1949)
Florian Cajori book A History of Mathematics
Source: A History of Mathematics (1893), p. 30 Reported in Memorabilia mathematica or, The philomath's quotation-book by Robert Edouard Moritz. Published 1914.