This book offers an introduction to the nature of mathematics, its history, and some of the curious individuals who have shaped it. It explores a range of fundamental ideas that can be appreciated without prior mathematical training. Highlighting the human side of mathematics and its shared lineage with philosophy, the book embraces the subject’s colorful history, incorporating original source material in the main text. Based on a course taught to non-science majors, it is intended for anyone with an interest in mathematics—including those whose last experience with algebra was less than enjoyable. This book offers an introduction to the nature of mathematics, its history, and some of the curious individuals who have shaped it. It explores a range of fundamental ideas that can be appreciated without prior mathematical training. Highlighting the human side of mathematics and its shared lineage with philosophy, the book embraces the subject’s colorful history, incorporating original source material in the main text. Based on a course taught to non-science majors, it is intended for anyone with an interest in mathematics—including those whose last experience with algebra was less than enjoyable. Stefan Steinerberger is a Professor of Mathematics at the University of Washington, Seattle. He is broadly interested in the area of analysis and its applicability to problems in applied mathematics. His research has been supported by the Austrian Science Fund, the National Science Foundation, the Institute for New Economic Thinking and the Alfred P. Sloan Foundation.