190 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1960 



the object becomes familiar to ns, whether by scientific knowledge or 

 by everyday use. 



8. INDIVIDUALITY OR "SAMENESS" 



After a certain wealth of association has come to outshine the core 

 of sensates, the latter is no longer needed to keep the complex together. 

 It persists even when the contact of our senses with the object tem- 

 porarily ceases. And more than that: the complex is latently con- 

 served even when the whole string is interrupted by our turning away 

 from the object to others and forgetting all about it. Indeed, this is 

 not exceptional, but a rule which — since we sometimes sleep — has no 

 exception. But we have adopted the useful device of filling these gaps. 

 We supplement the missing parts of the strings relating to pieces of 

 matter in our nearer and farther surroundings, to cover the periods 

 when we neither watch them nor think of them. When a familiar 

 object re-enters our ken, it is usually recognized as a continuation of 

 previous appearances, as being the same thing. The relative perma- 

 nence of individual pieces of matter is the most momentous feature of 

 both everyday life and scientific experience. If a familiar article, say 

 an earthenware jug, disappears from your room, you are quite sure 

 somebody must have taken it away. If after a time it reappears, you 

 may doubt whether it really is the same one — ^breakable objects in such 

 circumstances are often not. You may not be able to decide the issue, 

 but you will have no doubt that the doubtful sameness has an indis- 

 putable meaning — that there is an unambiguous answer to your query. 

 So firm is our belief in the continuity of the unobserved parts of the 

 strings I 



No doubt the notion of individuality of pieces of matter dates from 

 time immemorial. I suppose animals must have it in some way, and 

 a dog, when seeking for his ball that has been hidden, displays it very 

 plainly. Science has taken it over as a matter of course. It has re- 

 fined it so as safely to embrace all cases of apparent disappearance of 

 matter. The idea that a log which burns away first turns into fire, 

 then into ashes and smoke, is not alien to the primitive mind. Science 

 has substantiated it ; though the appearance in bulk may change, the 

 ultimate constituents of the matter do not. This was (in spite of his 

 occasional skepticism mentioned above) the teaching of Democritus. 

 Neither he nor Dalton doubted that an atom which was originally pres- 

 ent in the block of wood is afterward either in the ashes or in the 

 smoke. 



9. THE BEARING ON ATOMISM 



In the new turn of atomism that began with the papers of Heisen- 

 berg and of de Broglie in 1925 such an attitude has to be abandoned. 

 This is the most startling revelation emerging from the ensuing de- 



