One of the world's oldest living religions, born in the same ancient Indian ferment as Buddhism among the non-Vedic renouncers, and built around a single principle carried further than perhaps any other tradition has carried it: ahimsa, non-harm to every living being, down to the smallest. Its central teacher is Mahavira, by tradition the last of twenty-four ford-makers, though Jains hold the path itself to be eternal.
Some Jain ascetics, especially in the white-clad Svetambara orders, sweep the ground before each step, strain their drinking water, and wear a cloth over the mouth so as not to inhale a gnat. The strictest will not even farm, because the plow tears open the soil and kills the tiny lives within it. This is not eccentricity but the tradition followed to its furthest edge: a single conviction, that no living thing should be harmed, pursued more rigorously than almost anywhere else on earth. From it radiates a whole religion, and a whole ethics. It is the principle that, centuries later, helped shape Gandhi's nonviolence — though his version drew on several traditions.