174 THE PRINCIPLES OF SCIENCE 



cant example is the enduring eflFort to construe the variety of the 

 world in terms of a very few "elements." That attempt begins with 

 Thales, the earliest of the Ionian philosopher-scientists; and the 

 modern physicist, with his "fundamental particles," presses on in the 

 same endeavor. Generalizing "elements" to include intangibles like 

 force and energy, we find in Newton's Principia an expression of the 

 same striving, for he says: 



. . . the whole burden of [natural] philosophy seems to consist in 

 this— from the phenomena of motions to investigate the forces of na- 

 ture, and then from these forces [small in number and taken as 

 axioms] to demonstrate the other phenomena. 



Sambursky emphasizes the absolute continuity of the endeavor while 

 citing yet another example of it: 



The laws of conservation are now so essential a part of science that it 

 is hardly conceivable that we should be able to do without them or 

 that science should take any form which does not allow for the formu- 

 lation of such laws. The possibility of such foraiulation is implied in 

 the premise which the Milesian School considered self-evident: that 

 nature is capable of a rational explanation which reduces the number 

 of variables and replaces some of them by constant quantities in- 

 dependent of time or of the particular form of a given process. 



Penury. Each "quality" imputed to a premised entity figures as an 

 additional postulate. Our desire for parsimony of postulates thus 

 evokes a search for theoretical posits having the slenderest possible 

 qualitative endowment. But this last quest derives more fundamen- 

 tally and directly from the principle of intelligibility. Dingle makes it 

 a principle of rational thought that: 



. . . an entity which is postulated to explain a general propeiiy of 

 observable entities must necessarily lack that propeiiy. 



We reject theories that offer no more than a first step in a poten- 

 tially infinite regress. We find no sense of explanation in the attribu- 

 tion of the wetness of water to the wetness of water molecules, or of 

 the hardness of iron to the hardness of iron atoms. As well, we think, 

 explain the soporific action of opium by a dormative virtue inherent 

 in it. Today Heisenberg remarks diat: 



It is impossible to explain . . . qualities of matter except by tracing 

 them back to the behavior of entities which themselves no longer 



