Editing History of logic (section)

====Thales====
It is said Thales, most widely regarded as the first philosopher in the [[Greek philosophy|Greek tradition]],<ref>[[Aristotle]], Metaphysics Alpha, 983b18.</ref><ref name="CPM">{{cite book |author-last=Smith |author-first=William |title=Dictionary of Greek and Roman biography and mythology |date=1870 |url=https://archive.org/stream/dictionaryofgree03smituoft#page/1016 |page=1016 |publisher=Boston, Little}}</ref> measured the height of the [[pyramids]] by their shadows at the moment when his own shadow was equal to his height. Thales was said to have had a sacrifice in celebration of discovering [[Thales' theorem]] just as Pythagoras had the [[Pythagorean theorem]].<ref>T. Patronis & D. Patsopoulos {{cite book |url=http://journals.tc-library.org/index.php/hist_math_ed/article/viewFile/189/184 |title=The Theorem of Thales: A Study of the naming of theorems in school Geometry textbooks |publisher=[[Patras University]] |access-date=2012-02-12 |archive-url=https://web.archive.org/web/20160303171258/http://journals.tc-library.org/index.php/hist_math_ed/article/viewFile/189/184 |archive-date=2016-03-03 |url-status=usurped}}</ref>

Thales is the first known individual to use [[deductive reasoning]] applied to geometry, by deriving four corollaries to his theorem, and the first known individual to whom a mathematical discovery has been attributed.<ref>{{harv|Boyer|1991|loc="Ionia and the Pythagoreans" p. 43}}</ref> [[Indian mathematics|Indian]] and Babylonian mathematicians knew his theorem for special cases before he proved it.<ref>de Laet, Siegfried J. (1996). ''History of Humanity: Scientific and Cultural Development''. [[UNESCO]], Volume 3, p. 14. {{ISBN|92-3-102812-X}}</ref> It is believed that Thales learned that an angle inscribed in a [[semicircle]] is a right angle during his travels to [[Babylon]].<ref>Boyer, Carl B. and [[Uta Merzbach|Merzbach, Uta C.]] (2010). ''A History of Mathematics''. John Wiley and Sons, Chapter IV. {{ISBN|0-470-63056-6}}</ref>