THE STORY OF PHILOSOPHY2 The Lives and Opinions

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THE STORY OF PHILOSOPHY
teacher of Pericles, seems to have given a correct explanation of solar
and lunar eclipses; he discovered the processes of respiration in plants
and fishes; and he explained man's intelligence by the power of manipulation
that came when the fore-limbs were freed from the tasks of locomo-
tion. Slowly, in these men, knowledge grew into science.
Heraclitus (530-470 B. c.), who left wealth and its cares to live a
life of poverty and study in the shade of the temple porticoes at Ephesus,
turned science from astronomy to earthlier concerns. All things forever
flow and change, he said; even in the stillest matter there is unseen flux
and movement. Cosmic history runs in repetitious cycles, each beginning
and ending in fire (here is one source of the Stoic and Christian doctrine
of last judgment and hell) . "Through strife," says Heraclitus, "all things
arise and pass away. . . . War is the father and king of all: some he has
made gods, and some men; some slaves, and some free." Where there js_
no strife there is decay: "the mixture which is not shaken decomposes."
In this flux of change and struggle and selection, only one thing is con-
stant, and that is law. "This order, the same for all things, no one of gods
or men has made; but it always was, and is, and shall be." Empedocles
the idea of evolu-
(fl. 445 B. c., in Sicily) developed to a further stage
tion. 17
Organs arise not by design but by selection. Nature makes many
trials and experiments with organisms, combining organs variously;
where the combination meets environmental needs the organism survives
and perpetuates its like; where the combination fails, the organism is
weeded out; as time goes on, organisms are more and more intricately
and successfully adapted to their surroundings. Finally, in Leucippus (fl.
445 B. c.) and Democritus (460-360 B. c.), master and pupil in Thracian
Abdera, we get the last stage of pre-Aristotelian science materialistic,
deterministic atomism. "Everything," said Leucippus, "is driven by neces-
atoms and the void."
sity." "In reality," said Democritus, "there are only
Perception is due to the expulsion of atoms from the object upon the sense
organ. There is or have been or will be an infinite number of worlds; at
every moment planets are colliding and dying, and new worlds are rising
out of chaos by the selective aggregation of atoms of similar size and
shape. There is no design; the universe is a machine.
This, in dizzy and superficial summary, is the story of Greek science
before Aristotle. Its cruder items can be well forgiven when we con-
sider the narrow circle of experimental and observational equipment
within which these pioneers were compelled to work. The stagnation of
Greek industry under the incubus of slavery prevented the full development
of these magnificent beginnings; and the rapid complication of
political life in Athens turned the Sophists and Socrates and Plato away
from physical and biological research into the paths of ethical and
political theory. It is one of the many glories of Aristotle that he was
17 Cf. Osborn, From the Greeks to Darwin; and M. Arnold, Empedocles on Etna.