"Beauty, intrigue, paradox and surprise. Mathematics, in its true essence, is a deeply organic and intensely human enterprise and Bob and Ellen Kaplan are the masters of reveling in its delight and elucidating its richness. Hidden Harmoniesis a stunning book, taking the most classic theorem in mathematics and exposing its story, its human story, for what it really is: true poetry." James Tanton, PhD, author and educator, founding director of the St. Mark's Institute of Mathematics "...The authors succeed in explaining the arcane aspects of the subject, and they are diligent in situating the Pythagorean theorem within the historical rise of mathematics. That they revel in the subject is clear..." Wall Street Journal "Showing the theorem's endless versatility, the Kaplans and their logic- and symbol-permeated text will engage those who delight in doing the math." Booklist "Enthusiasm and wit make the material appealing even to readers who aren't mathematicians ... inspired." Kirkus "The book possesses an alluring lyricism and a good sense of humor, and it's often as fun to be around..." Anthony Doerr, Boston Globe