The Higher Usefulness of Science 67 



phenomena. The bar magnet is only the summation 

 of its magnetized molecules. The bar is magnetic be- 

 cause its constituent molecules are magnetic. That 

 seems to be, in essence, the usual mode of reasoning 

 about the phenomenon. Let us examine it somewhat 

 critically. We notice first of all that the molecular 

 conception of magnetism is always spoken of either as 

 an hypothesis, or, when the highest level of assurance 

 is reached, as a theory. No authority whom I have 

 consulted puts the magnetized molecules on the same 

 plane of certitude upon which he puts the magnetized 

 body. The base of reference in all testing of the 

 theory is the magnet itself. That is what all experi- 

 mentalists and mathematicians come back to finally 

 for deciding whether or not a particular aspect of the 

 hypothesis is valid. 



Reflect now on just what the molecular theory of 

 magnetism is. It supposes that magnetizable sub- 

 stances are composed of molecules each one of which 

 is a potential magnet whose axes of force point in all 

 directions, and that the conversion of such a substance 

 into the magnetic state consists in so shifting the 

 molecular axes that they no longer neutralize one an- 

 other by pointing in all directions, but point only to 

 the north and south poles. See what this really means. 

 It means that the magnetizable body is made up of 

 minute particles each one of which, though not in reality 

 a magnet, is so constituted that it can become one. 

 But under what conditions is this assumed ability of 



