This is the definitive edition of one of the very greatest classics of all time--the full Euclid, not an abridgement. Utilizing the text established by Heiberg, Sir Thomas Heath encompasses almost 2500 years of mathematical and historical study upon Euclid. This unabridged republication of the original enlarged edition contains the complete English text of all 13 books of the Elements, plus a critical apparatus which analyzes each definition, postulate, and proposition in great detail. It covers textual and linguistic matters; mathematical anayses of Euclid's ideas; classical, medieval, Renaissance, modern commentators; refutations, supports, extrapolations, reinterpretations, and historical notes, all given with extensive quotes. "The textbook that shall really replace Euclid has not yet been written and probably never will be, " Encyclopaedia Britannica.