XLIV PHILOSOPHICAL SOCIETY OF WASHINGTON. 
far enough away from the Epicurean atoms, but we are still work- 
ing with the atoms of pure metaphysics. ° 
It is equally in accordance with the chronological order of time, 
and the logical order of scientific ideas, that we should next turn 
to Newton. And of Newton, the greatest name in all physical 
philosophy, it need only be said that in his work on Optics he re- 
turned to a conception of atoms, which, except that it proceeds on 
the assumption of a Deity and of final cause, is substantially identi- 
cal with that of Leucippus, Democritus, and Epicurus. He says: 
“All these things considered [that is, the chemical facts he had 
just recited], it seems probable to me that God in the beginning 
formed matter in solid, massy, hard, impenetrable, movable parti- 
cles, of such sizes and figures, and with such other properties and 
in such proportion to space as most conduced to the end for which 
He formed them; and that these primitive particles, being solids, 
are incomparably harder than any porous bodies compounded,of 
them, even so very hard as never to wear or break in pieces—no 
ordinary power being able to divide what God himself made one 
in the first creation.” This definition reminds us of Lucretius. 
In continuation Newton adds: “ While the particles continue 
entire they may compose bodies of one and the same nature and 
texture in all ages; but should they wear away or break in pieces, 
the nature of things depending on them would be changed. Water 
and earth composed of old worn particles would not be of the same 
nature and texture now with water and earth composed of entire 
particles in the beginning. And, therefore, that nature may be 
lasting, the changes of corporeal things are to be placed only in the 
various separations and new associations, and motions of these 
permanent particles.” 
The very form of this last-cited statement carries us back to 
the cradle of the Atomic Philosophy.* But it is not so much 
the form of Newton’s statement which excites our admiration 
as the connection of thought in which it stands. The whole of 
* Anpdzpttos 03 xar Asdutrxog momjoaytss ta oyypata, THY Adhotwow 
nar chy yéveow & tobtwy motodat, Oraxptozt yey zat ovyxplost yéveow zat 
giopdy, taZ2¢ OF zat Hose adhoiwor. Aristotle: Izy: Tsvecsws zat 
Phopas, 1, 2,4. (CDidot’s ed., vol. 2., p. 454.) 
