234 SEE— TEMPERATURE, SECULAR COOLING 



[April 20, 



Strange as it may seem at first sight, it is owing principally to 

 the wide grasp and characteristic penetration of Aristotle that he 

 correctly put his discussion of earthquakes in the book which treats 

 of the phenomena of the air. For he observed the connection be- 

 tween earthquakes and volcanoes as clearly as any modern man of 

 science could do ; and having noticed that in eruptions vapors escape 

 from the earth and diffuse themselves in the atmosphere, he justly 

 concluded that earthquakes are due to the action of pent-up vapors, 

 even when they do not break through and escape to the surface. 

 Could Newton, Laplace, Fourier or any modern investigator reason 

 better than Aristotle has done on this point? In spite of some in- 

 evitable errors, due to the early time in which he lived, the penetration 

 which he shows must be indeed a matter of surprise to all thoughtful 

 students of the physics of the earth. 



It is obvious that one should not expect from the Greeks and 

 Romans highly finished theories, such as we find in some branches 

 of modern science. If their thought was characterized by general 

 soundness, it may justly excite our wonder. For with all the ad- 

 vantages of the vast learning of our time and the experience of 

 centuries, we cannot claim that the moderns have always been 

 equally fortunate. For example, in speaking of Tycho Brahe, 

 Laplace justly remarks that notwithstanding his great genius for 

 making astronomical observations he had little understanding for 

 physical causes, on which the science of the heavens might be estab- 

 lished; and the same remark applies to all except a few of the total 

 number of investigators of subsequent time. 



However many working hypothesis may be imagined, it is clear 

 that no real science can be developed until the true physical cause of 

 a phenomenon is discovered. So difficult is the discovery of causes 

 that in speaking of Posidonius, Strabo (" Geog.," Lib. II., Chap. Iv., 

 §2) says that ''he (Posidonius) is much too fond of imitating 

 Aristotle's propensity for diving into causes, a subject which we 

 (Stoics) scrupulously avoid, simply because of the extreme darkness 

 in which all causes are enveloped." This remark enables one to 

 understand why Aristotle, Posidonius and Archimedes stand so pre- 

 eminent among the ancients. 



Although the Romans had ample political and military instincts, 



