Listen, O wise one, to the ancient teachings as revealed by Dhanvantari and the sages of old. From the very bone of the body arises marrow; from marrow comes forth semen, and from semen, passion is born. Out of passion springs vigor, and along with it, the qualities of region, form, strength, power, time, and nature—all are interlinked in the wondrous tapestry of life. Having understood these subtle connections, one must approach treatment with discernment, always considering the potency of the medicine at hand. There are auspicious and inauspicious times: one should avoid administering remedies on Rikta lunar days, on Tuesdays, and under the constellations Mula, Bharani, and Krittika. Before beginning any treatment, it is right and proper to honor Lord Hari, the sacred cows, the twice-born, the moon, the sun, and the gods themselves. Only then, O learned one, should you listen to the sacred mantra and commence the administration of medicine. May Brahma, Daksha, the Ashvins, Rudra, Indra, Earth, Moon, Sun, Wind, Fire, the sages, the hosts of medicinal plants, the spirits, and the protectors all guard you as you undertake this noble work. Let this remedy be to you as elixirs are to the seers, as nectar is to the gods, and as the finest medicine is for the noble serpents—a true source of healing and strength. Understand also the nature of the regions where one dwells. A land dominated by wind and phlegm, with abundant trees and water, is known as marshy; its opposite, where these are lacking, is called arid. A region with some trees and water is considered mixed, and it is the arid land that is rich in bile, while the mixed region is regarded as balanced. The three humors—wind, bile, and phlegm—each have their own qualities. Wind is subtle, cold, and mobile. Bile is hot and pungent in three ways. Phlegm is stable, sour, unctuous, and sweet, and is said to confer strength. Like increases like, and opposites diminish each other: sweet, sour, and salty tastes increase phlegm and reduce wind, while pungent, bitter, and astringent tastes are windy and reduce phlegm. Pungent, sour, and salty tastes increase bile, but bitter, sweet, and astringent tastes destroy it. These effects are not from the taste alone, but from the post-digestive action of the substance. Substances with hot potency dispel phlegm and wind, while those with cold potency pacify bile. By their inherent power and action, these substances produce their effects, as the wise Sushruta is told. The seasons, too, have their role: in winter, spring, and summer, phlegm accumulates, is aggravated, and then pacified, in order. For wind, accumulation, aggravation, and pacification occur in summer, the rainy season, and at night, as well as in autumn. Bile follows its own course—in the rainy season, autumn, and early winter, these stages are described. The seasons beginning with the rains are of the nature of release, as are the three starting from early winter; those beginning with late winter and ending with summer are of the nature of absorption. The moon is said to have a releasing influence, while the sun is absorbing. As the moon moves through the three seasons beginning with the rains, it produces the tastes in turn: sour, salty, and sweet. The sun, traveling through the seasons starting with late winter, likewise generates the tastes in order. As the humors grow, one should gradually increase bitter, astringent, and pungent tastes, for only one strength increases at a time. As the humors diminish, so too do they decrease gradually, along with the nights, days, and the aging of humans. At the beginning, middle, and end, kapha, pitta, and vāyu become aggravated, each increasing at the start of its agitation. The period after their aggravation is called remission, which is brought about by both overeating and not eating. All diseases arise from the suppression or forceful release of natural urges. When eating, fill two parts of the stomach with food, and one part with drink, leaving space for vāyu and the other humors. In treating disease, the remedy should always be contrary to the cause. Thus is the essence declared: above and below the navel, and likewise at the anus and hips, lie the locations of strength, blood, pitta, and vāyu within the body. Yet know that all these are pervasive, especially vāyu. The heart, at the center of the body, is considered the seat of the mind. One who is thin, with little hair, restless, talkative, and with irregular digestion, is of vāta nature—sky-moving, wandering in dreams, prematurely gray, irritable, prone to sweating, and fond of sweet things. In dreams, one who sees radiant things is of pitta nature. The tamasic, rajasic, and sattvic types are also remembered thus. One who sees clear clouds in dreams is of kapha nature, and these types too are remembered as tamasic, rajasic, and sattvic. Pitta is aggravated by fear, by excessive water drinking, by eating heavy foods, and by lying down after eating. Kapha increases in those who are lazy. Knowing the diseases arising from vāyu and the others, one should pacify them according to their symptoms. The symptoms of vāta disorders are fracture of bones, astringency in the mouth, dryness, yawning, and goosebumps. Pitta disorders reveal themselves as yellowing of nails, eyes, and veins, bitterness in the mouth, thirst, burning, and heat. Kapha disorders show as laziness, excessive salivation, heaviness, sweetness in the mouth, and a desire for warmth. To pacify vāta, one should use oily and warm food, massage, and oil-drinking. Clarified butter, milk, and items cooled by the rays of the moon are best for pitta. Honey, oil of triphala, and exercise dispel phlegm. For the pacification of all diseases, meditation and worship of Lord Vishnu are also effective. Now, Dhanvantari speaks: “I will explain the characteristics of rasa and the other qualities of medicines; listen to their virtues. One who knows rasa (taste), potency, and post-digestive effect can protect kings and others alike. The tastes sweet, sour, and salty arise from Soma; bitter, pungent, and astringent are said to be from Agni, O mighty-armed one. The post-digestive effect of a substance is threefold: pungent, sour, or salty in nature. Potency is described as twofold: hot or cold.” Thus are the ancient truths revealed, for the well-being of all who seek knowledge and health.