ANNUAL ADDRESS OF THE PRESIDENT. LVII 
gen.” * Democritus knew nothing of hydrogen, but he saw as 
clearly and said as plainly as Dalton that the antecedent premise 
of all physical philosophy must be found in the metaphysical maxim 
that “out of nothing nothing comes, and that nothing which is can 
ever be annihilated.” 
And this maxim, with which the old Greek philosophy began, is 
about all of solid and sound that remains to us from the physical 
philosophizing of the ancients. It is true, as Mr. Balfour Stewart 
remarks, that the ancients had in some way grasped the idea of the 
essential unrest and energy of things; that they had the idea ot 
small particles or atoms as the constituent elements of matter, and 
divined the existence of an ethereal medium extending through all 
space; but there is no evidence at all to support the statement 
that any one or all of these doctrines proceeded from even a ru- 
dimental conception of “the most profound and deeply seated ot 
the principles of the material universe.” 
There is, however, one respect in which it may be justly said that 
Democritus stands at the head of the long line of natural philoso- 
phers who since his day have been explicating for us the structure 
of the physical universe. He was the first who ever attempted a 
purely mechanical solution of the problem of physical being. It is 
the singular glory of the atomic philosophers that alone, among the 
jarring schools of Greece, they saw that a science of the Universe 
was possible only on the assumption that the phenomena of the 
physical universe are bound together by necessary law, and this 
law mechanical in the modes of its operation. They had no science, 
it is true, in the modern sense of the word, but it is no small dis- 
tinction which they have won in standing at the head of an intel- 
lectual succession which embraces in its ranks a Copernicus and a 
Galileo, a Newton and a Laplace, a Dalton and a Faraday. { 
* Henry: Memoirs, &c., of Dalton, p. 88. 
{ Diog. Laert., sub voce ‘‘ Democritus,” where it is particularly recorded 
that he assumed as his point of departure the maxim ‘Out of nothing 
nothing comes,’’ &c. 
t‘‘ Was die Atomiker von ihren Vorgangern unterscheidet, ist nur die 
Strenge und Folgerichtigkeit mit der sie den Gedanken einer rein material- 
istischen und mechanischen Naturerklérung durchgefithrt haben; diese kann 
ihnen aber um so weniger zum Nachtheil gedeutet werden, da sie damit nur 
die Schliisse gezogen haben welche durch die ganze bisherige Entwicklung 
gefordert, und wozu in den Annahmen ihrer Vorginger die Vordersatze ge- 
geben waren.’”’ Zeller: Philos. d. Griechen, Erster Theil, 765. 
