Mathematics: Rhyme and Reason is an exploration of the aesthetic value of mathematics and the culture of the mathematics community. This book introduces budding mathematicians of all ages to mathematical ways of thinking through a series of chapters that mix episodes from the author's life with explanations of intriguing mathematical concepts and the stories of the mathematicians who discovered them. The chapters can be read independently, and most require only a background in basic high school algebra or geometry to appreciate the topics covered. Part personal memoir, part appreciation of the poetry and humanity inherent in mathematics, this entertaining collection of stories, theorems, and reflections will be of interest to anyone curious about mathematics and the human beings who practice it. In the interest of fostering a greater awareness and appreciation of mathematics and its connections to other disciplines and everyday life, MSRI and the AMS are publishing books in the Mathematical Circles Library series as a service to young people, their parents and teachers, and the mathematics profession.