"Mathematicians do not study objects, but the relations between objects; to them it is a matter of indifference if these objects are replaced by others, provided that the relations do not change. Matter does not engage their attention, they are interested by form alone. " Henri Poincaré, Science and Hypothesis, 1905 p. 25
http://www.gutenberg.org/files/37157/37157-pdf.pdf?Session_id=e7cf634055c54752ddcd3cf67af4d283d30ff9f2