PREFACE IX 



A word about the organization of this inquiry may come appro- 

 priately at this point. The table of contents will offer the reader some 

 general indications of the lines of argument to be pursued, and will 

 at the same time indicate to him the relations envisaged by the author 

 among the various sub-topics considered. Chapters I, II, and III 

 represent a discursive survey of the whole area to be explored. Here I 

 introduce the categories to be used subsequently in systematic anal- 

 yses of the many problems that emerge from the preliminary survey. 

 If these three opening chapters prove difficult, they need only be 

 skimmed at a first reading: their rationale will become evident after 

 the succeeding chapters have been read. The nature and organization 

 of the remaining nine chapters are dictated by the examination of the 

 anatomy of science that concludes Chapter III. The social milieu of 

 science is the subject in Chapter IV. In Chapter V the reader will find 

 a consideration of the various characteristics of scientific "laws," and, 

 in Chapter VI, a discussion of the nature and use of the empirical pro- 

 cedures deployed by scientists. The core of the book is represented by 

 Chapters VII, VIII, and IX, which explore in detail the principles and 

 theories that are the hallmarks of science. In the three concluding 

 chapters I have treated science as a social institution (in Chapter X), 

 science as an individual achievement ( in Chapter XI ) , and science as 

 a genuine discovery of the "real world" ( in Chapter XII ) . 



I should, perhaps, comment on the abundant use that has been 

 made of direct quotations. Sometimes they offer particularly happy 

 expressions of the points to be made; sometimes they serve to indi- 

 cate the sources of arguments not otherwise attributed; sometimes 

 they figure as citations of authority in areas of discourse where I my- 

 self can claim no authority; occasionally they may be no more than 

 landmarks in my own education— statements that first resolved prob- 

 lems that had bothered me. Above all, these quotations are used to 

 display faithfully the opinions of men who have themselves made 

 scientific history. I acknowledge with thanks the courtesy of the 

 many publishers, listed on p. v, who have permitted me to quote from 

 works appearing under their imprint. 



To deal adequately with all parts of the subject I have set myself, 

 one would have to be deeply versed in history, psychology, sociology, 

 and philosophy— not to mention all the individual sciences. Given a 

 keen awareness of my own limitations, I am particularly grateful for 

 the counsel I have received from friends and colleagues. I owe to 



