itted that each
kind of element has its distinctive personality, and he attempted to
visualize and describe the characteristics of the personality.

Thus while Anaxagoras tells us nothing of his elements except that they
differ from one another, Democritus postulates a difference in size,
imagines some elements as heavier and some as lighter, and conceives
even that the elements may be provided with projecting hooks, with the
aid of which they link themselves one with another. No one to-day takes
these crude visualizings seriously as to their details. The sole element
of truth which these dreamings contain, as distinguishing them from the
dreamings of Anaxagoras, is in the conception that the various atoms
differ in size and weight. Here, indeed, is a vague fore-shadowing of
that chemistry of form which began to come into prominence towards the
close of the nineteenth century. To have forecast even dimly this newest
phase of chemical knowledge, across the abyss of centuries, is indeed a
feat to put Democritus in the front rank of thinkers. But this estimate
should not blind us to the fact that the pre-vision of Democritus was
but a slight elaboration of a theory which had its origin with another
thinker. The association between Anaxagoras and Democritus cannot be
directly traced, but it is an association which the historian of ideas
should never for a moment forget. If we are not to be misled by mere
word-jugglery, we shall recognize the founder of the atomic theory of
matter in Anaxagoras; its expositors along slightly different lines in
Leucippus and Democritus; its re-discoverer of the nineteenth century
in Dalton. All in all, then, just as Anaxagoras preceded Democritus in
time, so must he take precedence over him also as an inductive thinker,
who carried the use of the scientific imagination to its farthest reach.

An analysis of the theories of the two men leads to somewhat the same
conclusion that might be reached from a comparison of their lives.
Anaxagoras was a sceptical, experimental scientist, gifted also with
the prophetic imagination. He reasoned always from the particular to the
general, after the manner of true induction, and he scarcely took a step
beyond the confines of secure induction. True scientist that he was,
he could content himself with postulating different qualities for
his elements, without pretending to know how these qualities could be
defined. His elements were by hypothesis invisible, he