THE PRINCIPLES OF SCIENCE 187 



Atomism. Of the appearances of change and permanence in our 

 world, Herachtus dismisses permanence as ilkisory, while Parmenides 

 so dismisses change. Wishing to dismiss neither, we forever seek to 

 found on permanence— on some element(s) of timeless identity we 

 willingly take for granted— our conceptualization of whatever is ob- 

 served to change with time. Change in the medium-sized world of 

 our experience we seek then to derive from permanence in either 

 macrocosm or microcosm, respectively enfolding or underlying the 

 everyday world. Initially the first possibility may seem more plau- 

 sible: the cycles of tides and seasons are obviously correlated with 

 cycles of moon and sun respectively. And astrology seeks the origin 

 of most or all terrestrial change in the macrocosm, in "influences" aris- 

 ing from the shifting juxtapositions of eternal bodies pursuing their 

 eternally appointed rounds. Mutability then derives from the im- 

 mutable, the "local" motions and changing dispositions of which are 

 not for us inconceivable. Only the millennial incompetence of astrol- 

 ogy finally discredits this possibility. 



The second alternative is the one Leucippus and Democritus ex- 

 plored. Again qualitative change is construed in term.s of local dis- 

 placements of the unchanging— here in a hypothetical microcosm, 

 the world of atoms. Thus, in Newton's phrasing, 



. . . the changes of corporeal things are to be placed only in the 

 various separations and new associations and motions of these per- 

 manent particles; . . . 



Slightly earlier, but some two millennia after Parmenides, Boyle had 

 maintained that: 



If an angel himself should work a real change in the [qualitative] 

 nature of a body, 'tis scarce conceivable to men, how he could do it, 

 without the assistance of local motion. 



Two centuries later du Bois-Reymond still saw things the same way: 



The scientific cognition of nature ... is the reduction of changes 

 in the physical world to the motions of atoms in accordance with cen- 

 tral forces independent of time ... It is a fact of psychological ex- 

 perience that our yearning for causal understanding is, for the time, 

 well satisfied whenever we succeed in making that reduction. 



Beyond conceptual attractiveness, the corpuscular view today offers 

 proven power. In all chemistry qualitative change is conceived in 



