viii PREFACE 



acters. Furthermore, it permits the field to achieve more 

 accurate formulation when the problems themselves have 

 become more or less standardized and organized. 



It seems certain that no finally satisfactory definition of 

 the field in question is possible today. Not only are most of 

 the problems still unsolved — that is quite to be expected in 

 an embryonic science — but for the greater part the prob- 

 lems have not even been clearly stated or precisely differen- 

 tiated from one another. It may be that the field has not 

 yet reached that stage of development which permits even 

 a tentative formulation of its boundaries and structure. 

 Apparently the only way to decide is to attempt such a for- 

 mulation and examine the results. If the theoretical descrip- 

 tion of the type of problem corresponds closely with the 

 actual field of literature, the formulation may be looked 

 upon with favor. Furthermore, the choice as to the most 

 adequate term for describing the field is still an open matter. 

 General use seems to have favored the term "philosophy of 

 science," though the phrase is not without some disadvan- 

 tages. Here, again, all that one can do is to use the term 

 consistently in some well-defined sense, and see whether any 

 confusion arises. Such a definition of the field of the philos- 

 ophy of science will be attempted in the following pages. 



The main practical considerations which have guided the 

 author in the arrangement and selection of material should 

 be stated at this point. The book has been written with a 

 definite view to textbook use. In recent years there has been 

 introduced into the colleges and universities of the country 

 an increasing number of courses in the philosophy of science. 

 Since the source material for such courses is to be found in 

 some hundreds of books, many of which contain only a few 

 pages of relevant subject matter, and in magazine articles 

 printed in periodicals not commonly found except in the 

 larger libraries, teachers have been somewhat at a loss for 

 supplementary readings. The present book has been written 

 in the attempt to include as much of this source material as 

 is possible, consistent with a unified presentation. Where 



