 According to hagiographic works, the Daoist immortals are historical, semi-historical, or entirely legendary persons who transcend the limits of ordinary human existence, sometimes by birth but usually by means of their practices. As described by Benjamin Penny (2000: 125–26), their powers include the ability to transform themselves into different creatures or objects; the possession of extraordinary bodies, devoid of signs of aging and capable of stunning feats; the skill of controlling people, animals, and objects by means of mastery of qi (the life-giving “breath”); the gift of healing; and the faculty of predicting the future. The main power possessed by the immortals, however, is certainly the ability to reach indefinitely long lifespans. It is especially in hagiographic works that the idea of human “perfectibility” is understood in a sense that is, at the same time, most elementary and most idealistic: not only an exceptional longevity, but also the immortality of the physical body.