BELIEFS
expedient to reserve this discussion of first principles
to the last chapters.
Let us begin by a summary, in the most general terms,
of what we know about the world we live in. Science, in
Meyerson's phrase, is the reduction of diversity to identity.1
The diverse, the brute irrational fact, is given by our senses.
But we are not content to accept diversity as so given. "We
have a hunger and thirst for explanation and, for the human
mind, explanation consists in the discovery of identity
behind diversity. Any theory which postulates the exist-
ence of identities behind diversities strikes us as being
intrinsically plausible.
Nature seems to satisfy the mind's craving; for, upon
investigation, it turns out that identities do in fact underlie
apparent diversity. But explanation in these terms is never
quite complete. The facts of sensation and of irreversible
change in time are irrationals which cannot be completely
rationalized by reduction to identity. Science recognizes
the specificity of things as well as their underlying sameness.
Hegel's mistake was to imagine that nature was wholly
rational and therefore deducible a priori. It would be
convenient if this were the case; but unfortunately it
Isn't.
The diversity of the material world has been reduced, so
far as such reduction is possible, to an ultimate identity.
All matter, according to the physicist, is built up, in a
limited number of patterns, out of units of energy which,
in isolation, seem to possess none of the qualities ordinarily
associated with matter in the mass. Between a billion sub-
atomic units and one sub-atomic unit there is a difference,
not only of quantity, but also of quality. The natural
sciences, such as physics, chemistry, biology, are concerned
with matter as built up into varying degrees of patterned
complexity. The specificity of things, immediately per-
1 See Chapter II.