“Spherical trigonometry and certain other theorems, to which the author has added a new one of frequent application, then serve for the solution of the problems which the comparison of the various directions involved can present.”
"Gauss's Abstract of the Disquisitiones Generales circa Superficies Curvas presented to the Royal Society of Gottingen" (1827) Tr. James Caddall Morehead & Adam Miller Hiltebeitel in General Investigations of Curved Surfaces of 1827 and 1825 http://books.google.com/books?id=SYJsAAAAMAAJ& (1902)
Context: In researches in which an infinity of directions of straight lines in space is concerned, it is advantageous to represent these directions by means of those points upon a fixed sphere, which are the end points of the radii drawn parallel to the lines. The centre and the radius of this auxiliary sphere are here quite arbitrary. The radius may be taken equal to unity. This procedure agrees fundamentally with that which is constantly employed in astronomy, where all directions are referred to a fictitious celestial sphere of infinite radius. Spherical trigonometry and certain other theorems, to which the author has added a new one of frequent application, then serve for the solution of the problems which the comparison of the various directions involved can present.
Help us to complete the source, original and additional information
Carl Friedrich Gauss 50
German mathematician and physical scientist 1777–1855Related quotes
Source: 1940s - 1950s, Introduction to Operations Research (1957), p. 8, cited in: R.L. McCown (2001) "Learning to bridge the gap between science-based decision support and the practice of farming". In: Aust. J. Agric. Res., Vol 52, p. 560-561
Anatol Rapoport. " Various meanings of “theory”." http://www.acsu.buffalo.edu/~fczagare/PSC%20504/Rapoport%20(1958).pdf American Political Science Review 52.04 (1958): 972-988.
1950s
Blood-Brotherhood and Other Rites of Male Alliance (2009).
Misc

Source: Modularity of Mind (1983), p. 126, partly cited in: Meredith Williams (2002) Wittgenstein, Mind, and Meaning: Toward a Social Conception of Mind. p. 104. Quote about the direction of information flow in perceptual and observer analysis.
review of All the Myriad Ways by Larry Niven http://jamesdavisnicoll.com/review/remember-when-niven-was-fun, 2015
2010s
Book A (sketchbook), p 31, c 1963: as quoted in Jasper Johns, Writings, sketchbook Notes, Interviews, ed. Kirk Varnedoe, Moma New York, 1996, p. 50
1960s

Source: On the Study and Difficulties of Mathematics (1831), Chapter I. Introductory Remarks on the Nature and Objects of Mathematics.