The first steps toward scientific medicine were taken around 2000 years ago when the stock of folklore about the curative properties of various substances and rituals was gradually classified. One of the earliest pharmacopoeias (ie, catalogs of medicines) was compiled by the Greek physician, pharmacist, and pharmacologist Dioscorides (ca AD 40-80). Dioscorides' classic pharmacopoeia,<i>De Materia Medica</i>, included detailed descriptions of and information on the preparation, specific indications, doses, and administration of medicines derived from plant, animal, and mineral sources during his and earlier centuries. The impact of this volume was so great that Dioscorides remained the leading authority on drugs through ensuing centuries until the dawning of "scientific" medicine and pharmacology in the 1700s and 1800s. John Riddle, the author of<i>Dioscorides on Pharmacy and Medicine</i>, is an eminent medical historian who provides what the reader might expect from the title of this book: a detailed accounting of the