240 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



Since the discussion in the following pages will consist of 

 illustrations considered from the point of view of the three- 

 fold analysis, a brief consideration of each of the sub- 

 problems will be of value at this point. 



(1) The first problem is essentially metaphysical, or, at 

 least, naturalistic. It is a problem of finding events of a 

 certain kind. Presumably, when the scientist uses such 

 words as 'time," "space," "substance," "number," and 



'cause' and when he asserts that nature is uniform, he is 

 referring to natural objects. The events to which he refers 

 may be very elusive, and hence not open to direct inspection. 

 In fact the existence of a problem in connection with such 

 concepts and propositions suggests that their reference to 

 events is not of an obvious kind. Certainly one must not 

 be led to expect nature to reveal precisely the kind of thing 

 that science means by these terms, and it may prove to be 

 the case that nature reveals something which is only very 

 remotely like the scientific notion. One must recall that the 

 mind often operates upon empirically given entities and 

 introduces elaborate modifications and transformations. But 

 it seems likely that science does not begin with just noth- 

 ing. Perfect points, lines, and levers, ideal gases, friction- 

 less motion, isolated individuals, economic cities, Utopias, 

 and the like are not pure imaginative fancies but modifica- 

 tions of actualities. The mind is able to abstract, generalize, 

 pass to limits, and form associations, with a freedom which 

 is apparently very great, but it always seems to start with 

 something which is empirically given and which exhibits a 

 certain plasticity to modifications in these directions. Hence 

 the problem of primary importance is to determine what this 

 empirically given stuff is. The task is essentially descrip- 

 tive, though it often involves the discovery and clarification 

 of data which have been implicitly rather than explicitly 

 recognized. Consequently it is a problem which,* as will be 

 seen immediately, offers serious difficulties. 



(2) Though the first problem is metaphysical, the second 

 is partly scientific and partly logical. It involves the exam- 



