Full context:   The four elements are attested in Egyptian cosmology long before their integration at a later date into the astrological corpus; they were also conceptualized by Presocratic philosophers. With Phythagoras and his disciples, the elements figure as symbols of the Tetrad; in the thought of Empedocles, they are the protagonists of a cosmological cycle;, increased, "roots of all things," full, immutable, eternal, material and endowed with consciousness, equal among themselves and in command of temporal cycles fixed by the order of destiny: "Along the course of the revolution, each of the elements takes its role: each one in its perishing transforms itself into the following and grows with the part fixed by destiny. They are thus the only ones with true being, and hence in their course, by mutual interchange, they become men and races of animals."