Arútam is the ancestral power-being and vision-soul at the heart of traditional Shuar religion. A boy of about eight would be taken by his father or an elder kinsman on a journey of several days to a sacred waterfall (tuna), there to fast on tobacco water and, sometimes, the strong hallucinogen maikua (Brugmansia), in hope that an arútam would appear, often as a terrifying or monstrous apparition. A seeker brave enough to run forward and touch it absorbed an arútam wakaní, an ancestral soul that made him strong, courageous, and proof against a natural death; accumulating several was thought to render a man almost invincible. The arútam is conceived less as a single personal deity than as an ancient diffuse power passing through successive holders, and it gives the title 'People of the Sacred Waterfalls' to Harner's classic ethnography.