THE SCOPE OF PHILOSOPHY 



more developed and the less developed sciences. 

 The sciences which have arrived at the highest 

 perfection are those which have carried quanti- 

 tative prevision to the farthest extent. Between 

 astronomy, which can foretell the precise mo- 

 ment at which a solar eclipse will begin a hun- 

 dred thousand years hence, and meteorology, 

 which cannot surely foretell from week to week 

 the state of the weather, there is an almost im- 

 measurable difference in scientific completeness. 

 The chemist can predict the exact quantity of 

 effect which will be produced by mingling a new 

 substance with any given compound, the pro- 

 perties of which have been studied ; while the 

 physiologist cannot surely predict the exact 

 amount of effect which will be produced by a 

 drug that is introduced into the organism ; and 

 we accordingly consider chemistry a much more 

 advanced science than physiology. And lastly, 

 let us note that the date which we habitually 

 assign for the commencement of any science is 

 the date at which its previsions began to assume 

 a definitely quantitative character. Dynamics is 

 said to have become a science when Galileo deter- 

 mined the increment of velocity of falling bodies. 

 Chemistry became a science when Lavoisier, De 

 Morveau, and Dalton discovered the exact pro- 

 portions in which the most important chemical 

 combinations take place. No science of heat 

 was possible until the invention of the ther- 



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