DOUBLE TAP TO ZOOM WITH PHONE OR TABLET Acknowledgments Acknowledging all the many friends and colleagues who have contributed to the conceptualization of this book over the years is impossible. But I must thank sev- eral people in particular who have helped to make it a reality. I am most indebted to Barbara Beatty, who insisted I read and include John Amos Comenius. I also want to thank George Scarlett for reading and commenting on many of the chapters. Punum Banta was kind enough to read the Montessori chapter and make many valuable suggestions. I owe enormous thanks to Kyra Ostendorf and Elena Futz for their thoughtful and thorough editing and fact-checking of all the chapters. They have made it a much better book than it would have been without their help. Last, but certainly not least, I want to thank my wife, Debra, for her gracious willingness to serve as a sounding board for, and gentle challenger to, my ruminations about each of the Giants. ix COPYRIGHTED MATERIAL