EVOLUTION (»K TllK SCIENTIFIC I N VESTIO ATOK. 'I'll 



theory 1)V :ul(]in<i' llinl the disljuu-e of Iho fixed stars was iiilinitely 

 orealei' than the diiiieiisions of the earth's oi-l)i(. Even tlie worM of 

 j)liih)S()|)hy was not yet ready foi' this eoiiceptioii, and, so I'ai' from 

 seein<i" the reasonabh'ness of the exi)hination, we lind PtohMny ai'gn- 

 in<i" aL>:ainst the rotation of the earth on <rronnds wliieh oarefnl oh- 

 ser\a(ions of the phenomena aronnd him wonld have shown to he ill- 

 fonndetl. 



Physiral >cience, if we can iip[)ly that term to an mico-ordinated 

 body of faets, was successfnlly cnltivated from the earliest times. 

 Sonu^thinu: mnst have b(>eii Known of the pi'opei'ties of metals, and 

 the art of extraetiii<>: them from their ores must have been practiced 

 from the time that coins and medals wore first stamped. The prop- 

 erties of the most common compounds were discovered by alchemists 

 in their vain search for the ])hilosopher's stone, but no actual pro<*:ress 

 worthy of the name rewarded the practiti(mers of the black art. 



lVrhai)s the first a})proach to a correct method was that of Archi- 

 medes, who by nnich thinkin*!; worked out the law of the lever, 

 reached the conception of the center of gravity, and demonstrated 

 the first princii)les of hydrostatics. It is remarkable that he did not 

 extend his researches into the i)henomena of motion, whether sponta- 

 neous oi- [)roduced by force. The stationary condition of the human 

 intellect is most strikingly illustrated l)y the fact that not until the 

 time of Leonardo Avas any substantial advance made on his discovery. 

 To sum u}) in one sentence the most characteristic feature of ancient 

 and mediaeval science, we see a notable contrast between the precision 

 of thought implied in the construction and demonstration of geomet- 

 rical theorems ancf the vague indefinite character of the ideas of 

 natural phenomena generally, a contrast which did not disajjpear 

 until the foundations of modern science began to be laid. 



We should miss the most essential point of the diiference between 

 meijia'val and modern learning if we looked upon it as mainly a dif- 

 fei-ence either in the precision or the amount of knowledge. The 

 development of both of these qualities would, under any circum- 

 stances, have been slow and gradual, but sure, ^^'e can hardly su})- 

 })ose that any one generation, or even any one century, would have 

 seen the complete substitution of exact for inexact ideas. Slowness 

 of growth is as inevitable in the case of knowledge as in that of a 

 growing organism. The most essential point of dilference is one of 

 those seemingly slight ones, the importance of which we are too apt 

 to overlook. Tt was like the droj) of l)lood in the wrong place, which 

 some one has told us makes all the difference between a i)hiloso])her 

 and a maniac. It was all the difl'erence betAveen a living ti-ee and a 

 dead one, between an in(>rt mass and a gi-owing organism. The tran 

 sition of knowledge from the dead to the living form must, in any 

 complete review of the subject, be looked upon as the really great 



