I met Iyengar in 2010, at his institute in Pune, a city about a hundred miles south of Mumbai, where students from all over the world travelled to study with the revered yoga master. Iyengar, the author of the 1966 yoga bible “Light on Yoga,” who died this week at the age of ninety-five. A central figure in this transformation was B. Until the twentieth century, educated Indians and Westerners alike tended to disdain the occult practices denoted by the term 'hatha yoga.' “We have nothing to do with it here, because its practices are very difficult and cannot be learnt in a day, and, after all, do not lead to much spiritual growth,” wrote Swami Vivekananda, who did much to popularize yoga philosophy in the West with his 1896 book, “Raja Yoga.” Only in the modern era has hatha yoga been transformed into a wholesome, accessible regimen for health and well-being. There are instructions for drawing discharged semen back into the penis, so as to overcome death, and for severing the tendon connecting the tongue to the bottom of the mouth, and lengthening it so that it can touch the forehead.

There are no sun salutations, no downward-facing dogs or warriors. Fifteen poses appear in the “Hatha Yoga Pradipika,” most of them seated or supine. Instructions for postures, or asanas, appeared much later, in medieval tantra-inflected texts, such as the “Hatha Yoga Pradipika.” Even in those works, however, you won’t find many of the positions taught today as yoga. Yoga, the sutras say, “is the restriction of the fluctuations of consciousness.” The total of their guidance about posture is that it should be “steady and comfortable.” This requires an imaginative leap, because the yoga sutras say next to nothing about physical poses their overriding concern is the workings of the mind.

In contemporary yoga classes, teachers often speak of Patanjali’s “Yoga Sutras,” a philosophical text compiled around two thousand years ago, as the wellspring of the practice. In Eka Pada Setu Bandha Sarvangasana (bridge pose), in Bangalore, 1989.

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