Book excerpt: This comprehensive guide to healing synthesizes the principles and practices of Hippocratic, Chinese, Ayurvedic, and Persian medicine, and includes the first English translation of one of the handbooks of Avicenna, whose writings have been classics in herbal and dietetic medicine for more than 1,000 years. Based on the philosophy that "food is the best medicine," Avicenna's canon provides simple and effective diagnostic techniques and therapies for maintaining health and strengthening the immune system. Includes a botanical guide for the 100 most-used healing herbs and recommended treatments for 400 conditions, including diet and nutrition, herbology, and aromatherapy.