MOTION, FORCE, MATTER 345 



venient to talk in terms of bodies and particles as though 

 they were at points, and at instants, and exhibited forces. 

 Upon the basis of careful operational derivation one should 

 say, rather, that the collection of measured values exhibits a 

 dominant spatial value, or temporal value, or force value. As a 

 result of the awkwardness of this expression the scientist still 

 retains the terminology of the substratum, though he may ad- 

 mit that this terminology is a mere convenience and is not to 

 be taken at its face value. Scientific matter may consequently 

 be defined in terms of the particle, as that which exhibits cer- 

 tain measurable spatial, temporal, and force properties. 



In summary, matter at the empirical level is simply a 

 group of qualities, or aspects, which seem to act essentially 

 as a unit; fundamental among these aspects are those 

 associated with space, time, and force. At the scientific level 

 matter is simply the refinement which is introduced into this 

 concept when the attempt is made to determine precisely 

 what its spatial and temporal locations are, and how intense 

 is its force manifestation. This results in the definition of 

 particle, either as that which exhibits a number of measured 

 values, or as the complex itself of these measured values. 

 The operational route employed in this transition is such as is 

 involved in the passage from empirical space, time, and force 

 to the scientific refinements of these notions. 



REFERENCES 



C. D. Rroad, Scientific Thought (New York: Harcourt, Rrace, 



1923), Chaps. Ill, IV, V, VII, XI. 

 Victor Lenzen, Physical Theory (New York: Wiley, 1931), 



Chaps. IV, XV. 

 R. R. Lindsay and H. Margenau, Foundations of Physics (New 



York: Wiley, 1936), Chap. III. 

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



1923), Chap. VIII. 

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



1927), Chaps. XXIII, XXVII. 

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



1915), lects. IV, VI. 

 Philosophy (New York: Norton, 1927), Chap. XXVI. 



