C. K. Raju
While mathematics was central to many ancient civilisations like Mesopotamia, Egypt, China and India,
there is no clear evidence that they used proofs
(p. 287, Class IX, Appendix 1)
In fact, Babylonians and Egyptians used geometry mostly for practical purposes and did very little to develop it as a systematic science. But in civilisations like Greece, the emphasis was on the reasoning behind why certain constructions work. [Emphasis original]
The Greeks were interested in establishing the truth of the statements they discovered using deductive reasoning (see Appendix 1)." (p. 79)
"However, each statement in the proof has to be established using only logic. … Beware of being deceived by what you see (remember Fig A1.3)!" [Appendix 1, p. 301, emphasis original]
"The only way to be sure that something is true is to prove it" (Appendix 1, p. 296)
mathematics is… unprofitable. Is mathematics… useful, as other sciences such as chemistry…are? …I shall ultimately say No (Mathematician's Apology, p. 8)
A mathematician, like a painter or a poet, is a maker of patterns…The mathematician’s patterns…must be beautiful; Beauty is the first test(pp 13-14)
It may be very hard to define mathematical beauty, but…that does not prevent us from recognizing… it.