ANALYSIS OF SCIENTIFIC CONCEPTS 241 



ination of actual scientific doctrine and procedure with a 

 view to determining the meaning of certain concepts such as 

 "time," "space," "matter," "number," and "cause," and 

 the truth value of certain propositions such as the assertion 

 of the existence of a uniform and objective nature. Unfor- 

 tunately, however, this problem is also complicated by the 

 fact that the concepts and propositions in question function 

 in science in an implicit as well as an explicit way. Hence it 

 does not suffice merely to ask the scientist what he means 

 by these symbols, for he may never have taken the trouble 

 to think about them consciously. Consequently, he may 

 not be able to tell what they mean, or what he says about 

 them may be contradicted by the way in which he uses 

 them, or his description of them may involve a circular 

 process such as Eddington describes * as the cyclic method 

 in physics, in which potential is defined in terms of interval, 

 interval in terms of scale, scale in terms of matter, matter 

 in terms of stress, and stress in terms of potential again. 

 The point is that the problem of determining the meaning 

 of such symbols is not merely a scientific problem but also 

 a logical problem. It involves such considerations as the 

 analysis of assumptions and preconceptions, the examination 

 of the structure of logical systems, and ascertainment of the 

 function of measurement in the sciences. It should reveal, 

 for example, in combination with the problem of the em- 

 pirical foundation of scientific concepts, the essential dif- 

 ference between the time which is assumed by the physicist 

 and the time which is revealed in direct perception as the 

 actual going-on of events, or the space which is implicit in 

 geometry and the space observed as the relations of distance 

 and direction between natural objects. The fact that the 

 same word is used to describe the two notions in each case 

 does not imply that the notions are identical. 



(3) The third problem is almost entirely logical, though 

 the border-line between the logical and the psychological 

 aspects is not sharply drawn. It may be formulated either 



1 Nature of the Physical World, pp. 260-265. 



