fragments we find nothing about rarefaction and condensation. The expression used is "exchange" (fr. 22), a very good name for what happens when fire gives out smoke and takes in fuel instead.
It has been pointed out that, in default of Hippolytos, our best account of the Theophrastean doxography of Herakleitos is the fuller of the two accounts given in Laertios Diogenes. It is as follows
His opinions on particular points are these:
He held that Fire was the element, and that all things were an exchange for fire, produced by condensation and rarefaction. But he explains nothing clearly. All things were produced in opposition, and all things were in flux like a river.
The all is finite and the world is one. It arises from fire, and is consumed again by fire alternately through all eternity in certain cycles. This happens according to fate. Of the opposites, that which leads to the becoming of the world is called War and Strife; that which leads to the final conflagration is Concord and Peace.
He called change the upward and the downward path, and held that the world comes into being in virtue of this. When fire is condensed it becomes moist, and when compressed it turns to water; water being congealed turns to earth, and this he calls the downward path. And, again, the earth is in turn liquefied, and from it water arises, and from that everything else; for he refers almost everything to the evaporation from the sea. This is the path upwards. R.P. 36.
He held, too, that exhalations arose both from the sea and the land; some bright and pure, others dark. Fire was nourished by the bright ones, and moisture by the others.
He does not make it clear what is the nature of that which surrounds the world. He held, however, that there were bowls in it with the concave sides turned towards us, in which the bright exhalations were collected and produced flames. These were the heavenly bodies.
The flame of the sun was the brightest and warmest; for the other heavenly bodies were more distant from the earth; and for that reason gave less light and heat. The moon, on the other hand, was nearer the earth; but it moved through an impure region. The sun moved in a bright and unmixed region
