This book focuses on plant systematics and evolution, with special interest on the history and philosophy of botanical classification. Tracing the history of how humans have dealt with ordering the plant world is very much a glimpse of how human culture and science have progressed over the past 2000 years.  The objective in this book is to present ideas on plant classification beginning with classical Greek and Roman scholars, through the Middle Ages, into the Renaissance, and finally to the modern 21st century. Significant quantitative methods in classification have originated within the past 70 years, which have never before been integrated with previous historical perspectives.  Most textbooks of systematic botany contain an historical introduction or perhaps a chapter on the history of classification, but this book presents much greater detail on the classifications themselves and the cultural dimensions of the different time periods. Biographical detail is also provided to give a better appreciation of the individual botanists who have contributed new ideas in the search for maximally predictive systems.