Quotations from The First Philosophers of Greece (1898) edited and translated by Arthur Fairbanks, unless otherwise cited.
These [elements] never cease changing place continually, now being all united by Love into one, now each borne apart by the hatred engendered of Strife, until they are brought together in the unity of the all, and become subject to it.
Bk. 1, line 66; p. 165
But come, hear my words, for truly learning causes the mind to grow. For as I said before in declaring the ends of my words: Twofold is the truth I shall speak; for at one time there grew to be the one alone out of many, and at another time it separated so that there were many out of the one; fire and water and earth and boundless height of air, and baneful Strife apart from these, balancing each of them, and Love among them, their equal in length and breadth.
Bk. 1, line 74; pp. 167-9
A twofold tale I shall tell: at one time it grew to be one alone out of many, at another again it grew apart to be many out of one. Double is the birth of mortal things and double their failing; for one is brought to birth and destroyed by the coming together of all things, the other is nurtured and flies apart as they grow apart again. And these things never cease their continual exchange, now through Love all coming together into one, now again each carried apart by the hatred of Strife. So insofar as it has learned to grow one from many, and again as the one grows apart [there] grow many, thus far do they come into being and have no stable life; but insofar as they never cease their continual interchange, thus far they exist always changeless in the cycle.
There is an utterance of Necessity, an ancient decree of the gods, eternal, sealed fast with broad oaths: whenever any one defiles his body sinfully with bloody gore or perjures himself in regard to wrong-doing, one of those spirits who are heir to long life, thrice ten thousand seasons shall he wander apart from the blessed, being born meantime in all sorts of mortal forms, changing one bitter path of life for another.
"On Purifications", line 369; p. 205
For before this I was born once a boy, and a maiden, and a plant, and a bird, and a darting fish in the sea.
"On Purifications", line 383; p. 207
This is not lawful for some and unlawful for others, but what is lawful for all extends on continuously through the wide-ruling air and the boundless light.
Alcmaeon was, says [J.] Wachtler, the first who attempted to explain the phenomenon of sound and our perception of it by reference to the structure of the ear itself. Empedocles to some extent follows or agrees with him. ...Empedocles teaches that hearing is caused by the impact of the air-wave against the cartilage which is suspended within the ear, oscillating as it is struck, like a gong.
He tried to address the problem of change by saying that there is not one fundamental arche but four—earth, water, air, and fire—which generate all the material substances in nature by mixing together in various ways under the influence of forces he called Love and Strife.
The Greeks elaborated several theories of vision. According to the Pythagoreans, Democritus, and others vision is caused by the projection of particles from the object seen, into the pupil of the eye. On the other hand Empedocles, the Platonists, and Euclid held the strange doctrine of ocular beams, according to which the eye itself sends out something which causes sight as soon as it meets something else emanated by the object.