Lives and Opinions of Eminent Philosophers

​His general doctrines were as follows: that all things are composed of fire and are resolved into it; that all things come to pass according to fate, and existing things are attuned through the conflict of opposites; and that all things are full of souls and spirits. He also spoke about all the affections that occur in the cosmos, and maintained that the sun is of the size it appears to be. The following is also quoted from him: "You could not discover the limits of the soul, though you walked and traveled every path; so deep a logos does it possess." He used to call conceit a 'sacred disease' and say that sight is deceptive. At times, however, he expresses himself in his treatise with brilliance and clarity, so that even the dullest person can easily understand and receive an elevation of soul; the conciseness and weight of his expression are beyond compare.

​His particular doctrines are as follows: that fire is the element, and all things are an exchange for fire, coming into being by rarefaction and condensation. Yet he sets nothing forth clearly. He holds that all things come to be through contrariety, that the whole flows like a river, that the universe is finite, and that the cosmos is one; that it is generated from fire and is in turn consumed by fire at certain recurring periods alternately through all eternity, and that this takes place according to fate. Of the contraries, that which leads to generation is called war and strife, while that which leads to conflagration is called agreement and peace, and the change is a 'road up and down', according to which the cosmos comes to be.

​For fire, when condensed, becomes moist, and when compacted together becomes water; water, when solidified, turns into earth; and this is the road downward. Again, in turn, the earth liquefies, from which water comes to be, and from this the remaining things, since he refers nearly everything to the exhalation from the sea; and this is the road upward. Exhalations arise from both earth and sea, some bright and pure, others dark; fire is increased by the bright exhalations, moisture by the others. What the surrounding atmosphere is like, he does not make clear; however, he says that there are in it bowls turned with their hollow sides toward us, in which the bright exhalations collect and produce flames, which are the heavenly bodies.

​The flame of the sun is the brightest and hottest. For the other heavenly bodies are farther removed from the earth, and on this account shine and warm less, while the moon, being closer to the earth, does not travel through a pure region. The sun, however, moves in a transparent and unmixed realm and keeps a measured distance from us; wherefore it warms and illuminates more. Eclipses of the sun and moon occur when the bowls are turned upward; and the monthly phases of the moon take place as its bowl is gradually turned round within itself. Day and night, months, annual seasons, years, rains, winds, and similar phenomena come to be in accordance with the different exhalations.

​For the bright exhalation, having kindled into flame in the circle of the sun, produces day, while the opposite exhalation, when it gains the mastery, brings about night; and the heat increasing from the bright exhalation produces summer, while the moisture abounding from the dark exhalation creates winter. Conformably with these principles, he also gives causal accounts of the other phenomena. But concerning the earth he declares nothing as to what sort of thing it is, nor indeed concerning the bowls. These, then, were his opinions. As for the circumstances concerning Socrates, and what he said upon encountering the treatise when Euripides brought it to him, as Ariston says, we have related them in the life of Socrates.