MOTION, FORCE, MATTER 341 



aspects. These are collected together by the same motives 

 which led us to regard the wall-paper as one thing, namely a 

 combination of sensible continuity and causal connection." 1 



3. Location and continuous extension in space. The com- 

 plex exhibits relations of distance and direction in space to 

 other complexes. This feature of matter is commonly con- 

 sidered as one of its most basic properties. Furthermore, 

 at the empirical level matter is also extended, and therefore 

 exhibits shape and size. Moreover, it has spatial identity; 

 i.e., it occupies an unbroken extent. Finally, by virtue of its 

 location in space it is capable of motion, since it is not tied 

 down to one point in space rather than to another. 



4. Force. One element of the complex is that property 

 which is empirically revealed as force. This shows itself 

 both in a relative impenetrability, exhibited in the resistance 

 which the complex offers to pressure, and in weight, ex- 

 hibited in the resistance which the complex offers to move- 

 ment away from the earth. The property of force is also 

 considered to be one of the most basic properties of matter. 

 Matter is what one bumps against in the dark, and what one 

 experiences when he carries a heavy suitcase. 



5. Secondary qualities. In addition, matter is presumed to 

 possess certain qualities such as heat, color, sound, taste, 

 and odor, which, because of their great variability, are not 

 taken as defining properties. Some of them may, on occa- 

 sions, be completely lacking. 



matter: scientific content 



Matter as it functions in science is a refinement of em- 

 pirical matter. The common practice in science involves the 

 substitution of more precise terms for the essentially vague 

 terms applicable at the empirical level. Lenzen uses the 

 term "body' to designate this basic entity of physical 

 science. "A thing considered merely from the point of view 

 of physical properties will be called a body; that is, a body 

 is something which has general measurable properties and 



1 Bertrand Russell, Our Knowledge of the External World, p. 106. 



