92 RITTER. . 



can to find and examine the creatures where nature has placed them. 

 True, the biologist has one great advantage over the astronomer: 

 not only can he actually get starfishes into his hands, but he can take 

 many of them — or the cadavers of them — home with him. In a 

 word, the biologist has the advantage of being able to study in his 

 laboratory, and by experimentation, the bodies themselves which are 

 the subject-matter of his science. 



These general reflections lead to a still more general reflection on 

 the character of the various sciences, which may be introduced by 

 the question: How is it that physics and chemistry are so largely 

 sciences of the laboratory and of experiment as to make them always 

 stand as types of the experimental sciences? The reply is that these 

 sciences are not natural sciences in the full sense ; that is, in the sense 

 of dealing, each in itself, with a delimited province of nature. They 

 are sciences which concern themselves with certain elements and 

 attributes of all nature, but not exhaustively with any portion of 

 nature. Especially they do not deal with forms and changes in the 

 time series which all natural bodies undergo. They are not natural 

 history sciences. Gravitation is one and the same to the physicist 

 whether manifested by a human body or an iceberg. Light is light, 

 so far as fundamentals go, whether its source be a lighthouse, a fire- 

 fly, or a sun. Similarly, it is all the same to the chemist whether his 

 sample of potassium, provided it is pure, is extracted from a kelp 

 plant or a crystal of feldspar. 



On the other hand, the several natural history sciences aim to deal 

 exhaustively with all the phenomena presented in their respective 

 domains of nature. 



These remarks appertain to such common-places' in modern science 

 that the making of them would not be justifiable but for certain impli- 

 cations they bear, which have not received due recognition in the 

 methodology of natural knowledge. The one of these implications 

 which concerns us at present may be expressed thus : The peculiarities 

 of the two groups of science, as indicated, namely, the group character- 

 ized by dealing with definitive portions of nature only, and that 

 characterized by dealing with particular attributes only of all bodies, 

 brings it to pass that the two groups supplement and depend upon 

 each other in a more fundamental way than has been fully recognized 

 by the methods actually used in either group. That the natural 

 .history sciences can reach full rounding-out only by supplementing 

 their own particular discoveries and methods by those of physics and 

 chemistry has received more recognition than has the fact that physics 



