252 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



point out further directions for research. This represents 

 the condition of the problem today. 



Since the following chapters are considered merely as 

 illustrative, they will be confined to the problem of the 

 meaning of the scientific concepts, and no reference will be 

 made to the problem of the validity of assumptions. The 

 procedures are essentially the same in the two cases. The 

 neglect of this latter problem is merely a convenience of 

 presentation, and should not be considered as a judgment 

 as to its unimportance. 



REFERENCES 



Th. Ribot, Evolution of General Ideas (Chicago: Open Court, 1897). 

 Bertrand Russell, Analysis of Matter (New York: Harcourt, Rrace, 



1927), esp. Chap. I. 

 Our Knowledge of the External World (Chicago: Open Court, 



1915). 

 C. D. Broad, Scientific Thought (New York: Harcourt, Brace, 



1923), introd., Chap. I, also Part II. 



E. W. Hobson, Domain of Natural Science (New York: Macmillan, 



1923). 

 K. Pearson, Grammar of Science (New York: Macmillan, 1911). 



F. Enriques, Problems of Science (Chicago: Open Court, 1914). 



