830 THE POPULAR SCIENCE MONTHLY. 



cient to have changed his opinion ; for metaphysical conceptions, like 

 spiritual substances, yield to no carnal weapons. 



Herein consists the great danger in the introduction of abstractions 

 into scientific discussions. Let them once be assumed to have an ex- 

 istence outside the concretes from which they are formed and the 

 tendency with many is to consider them in this light and no argu- 

 ment, based upon the observation of phenomena, is sufficient to over- 

 throw them. It can not be too strongly impressed upon the minds of 

 all that science has nothing to do with such conceptions. As science 

 consists in the observation of phenomena and the deduction of the 

 laws of their orderly occurrence, and as scientific hypothesis consists 

 in the prediction of the order of the future occurrence of phenomena 

 and the linking together of diverse phenomena under an assumed 

 order, we see that there is no place where these realistic conceptions 

 can enter. Their sphere, if anywhere, is in metaphysics and theology. 

 Scientists should exercise the utmost care not to misapprehend their 

 own terms, and should then compel acquiescence in the meaning they 

 give to them. Looseness in the use of words is one cause of the in- 

 definiteness that pervades the controversy between the scientists and 

 the theologians. 



Force, cause, matter, and science itself are abstract terms, and 

 when analyzed into their concretes will assume a meaning very differ- 

 ent from that often given them. All that we scientifically know of 

 force is, that it connotes the presence of motion (i. e., things moving) 

 under different conditions. These we separate into actual and poten- 

 tial motion, and the cause of the motion into actual and potential force 

 or energy. Here the necessity of the use of these abstract terms is at 

 once apparent, as we can scarcely make an assertion without employ- 

 ing them. Cause, as in the above-mentioned case of law, is simply the 

 preceding conditions of any phenomenon, and in the absence of which, 

 as far as we know, it can not occur. Likewise matter, the most " real " 

 of all abstractions, is, scientifically speaking, merely the symbol of a 

 congeries of the phenomena of extension ; and Professor Tyndall was 

 speaking entirely within scientific bounds when he said he discerned 

 in it the promise and potency of all forms of life. This did not in the 

 least prejudice the materialistic-idealistic controversy as to its ultimate 

 constitution. In his case he had repeatedly distinctly avowed his non- 

 acceptance of metaphysical materialism, and in a few concise sentences 

 had adduced a stronger argument against that belief than can easily 

 be found in the literature of the subject. The same may be said about 

 the use of the terra " vitality " by Professor Huxley and its relegation 

 by him to the limbo of other defunct " itys." This, which has never 

 ceased to be a red flag in the face of bellicose clergymen, was entirely 

 within his province, and was merely a fine example of the exactness 

 of definition of modern scientific nominalism. This misconception of 

 the scientific use of abstraction appears in almost all the current criti- 



