BOOK VI

TREATING OF EARTHQUAKES

CHAP.		PAGE
I.	Earthquake at Pompeii and the alarm it caused, with many abandoning Campania as a residence altogether. If the solid earth fails, what can be done? Refuge from tempests, fire, thunderstorms, and war is possible, but not from earthquakes. However: (1) The entire earth is subject to such movement; we cannot escape by changing our location—Tyre, Asia Minor, and Achaia have all suffered. (2) Death is the same in whatever form it comes; the circumstances do not matter. A stone is no different from a mountain . . . . .	221
II.	We cannot escape death. The hopeless find refuge in despair. Knowledge of our frailty and mortality is our true solace. Death must come; a death with circumstance is perhaps even to be preferred. In an earthquake, the earth shows itself to be as mortal as men are . . . . . . . . .	225
III.	Our fears are due to ignorance. Through a lack of a philosophical view of the universe, we consider phenomena strange when they are merely rare, such as eclipses. Fear may be removed by knowledge .	228
IV.	The study of such problems is the most worthy; it reveals the secrets of nature and is disinterested. At the same time, it is highly profitable . . . . . . . .	229
V.	Various explanations of earthquakes have been suggested. Earlier ones are crude but should not be despised. Every subject develops as time passes. Gratitude is due to the investigators who first dared to question nature . . . .	230
VI.	The cause of earthquakes is by some said to be water. Thales of Miletus explains how this happens, but he must be wrong: the analogy of a ship sailing the ocean does not apply to the earth (compare III. xiii.) . . . . . . . . . .	231
VII.	Water may be the cause, but it might operate in quite different ways than those supposed by Thales. Storms in subterranean seas could cause earthquakes . . . . . . . .	233
VIII.	There must be such subterranean water. The Tigris and Arethusa prove it. Nero, the virtuous and truthful, sent two officers to investigate the sources of the Nile; their account confirms this assumption . . . . . . . .	235
IX.	Fire is another alleged cause. It either bursts out through opposing obstacles, as in the clouds (Anaxagoras), or burns away the foundations, causing subsidence in that spot . . .	236
X.	Pieces of the earth falling in simply due to the decay of age may produce the effect without fire or any external influence. This is Anaximenes' opinion . . . . . . . .	237
XI.	Some suppose that fire causes earthquakes by expanding the vapor it forces out of subterranean waters . . . . . . . . . . . .	238
XII.	Archelaus sets down the cause as air pressing up the earth's internal wind, which is already condensed to the bursting point .	239