О природе
In the older editions, it is to this work that editors attributed the story about souls, where we are told that there were once spirits who lived in a state of bliss, but having committed a crime (the nature of which is unknown) they were punished by being forced to become mortal beings, reincarnated from body to body. Humans, animals, and even plants are such spirits. The moral conduct recommended in the poem may allow us to become like gods again. If, as is now widely held, this title "Purifications" refers to the poem "On Nature", or to a part of that poem, this story will have been at the beginning of the main work on nature and the cosmic cycle. The relevant verses are also sometimes attributed to the poem of "On Nature", even by those who think that there was a separate poem called "Purifications".