round our head; and that the sun is hid, not by being under the earth, but because covered by the higher portions of the earth, and on account of the greater distance that he is from us. But that the stars do not emit heat on account of the length of distance; and that the winds are produced when the condensed air, becoming rarified, is borne on; and that when collected and thickened still further, clouds are generated, and thus a change made into water. And that hail is produced when the water borne down from the clouds becomes congealed; and that snow is generated when these very clouds, being more moist, acquire congelation; and that lightning is caused when the clouds are parted by force of the wdnds; for when these are sundered there is produced a brilliant and fiery flash. And that a rainbow is produced by reason of the rays of the sun falling on the collected air. And that an earthquake takes place when the earth is altered into a larger [bulk] by heat and cold. These indeed, then, were the opinions of Anaximenes. This [philosopher] flourished about the first year of the lviii. Olympiad.
Chapter vii.
Anaxagoras—his Theory of Mind—recognises an Efficient Cause—his Cosmogony and Astronomy.
After this [thinker] comes Anaxagoras,[1] son of Hegesibulus,[2] a native of Clazomenæ. This person affirmed the originating principle of the universe to be mind and matter; mind being the efficient cause, whereas matter that which was being formed. For all things coming into existence simultaneously, mind supervening introduced order. And material principles, he says, are infinite; even the smaller
