tion.
This need seems never to have lapsed or changed its nature. All along
both driving power and direction, it has been the one fixed factor in a
long process in which all else has been fluctuating, contingent, and
imperfect--all else except the nature of the materials and the
principles of mechanics, which, too, are seen in the end to have been
mutely conspiring toward the result. Essential human nature, it seems
clear, does not and happily cannot change. Spiritual progress, in this
ultimate optimism, means simply clearer vision, completer knowledge, and
a less petulant and self-assertive habit of insistence upon the details
of particular purposes as individual "impulse" and "idiosyncrasy" define
them. We fortunate beings of today have available, in the various
departments of our life, certain instrumentalities, and to these our
interests attach. These interests of ours in their proportional strength
(so the argument runs) express our native and generic constitution in so
far as this constitution has been able as yet to achieve outward
expression and embodiment. And accordingly, in interpreting the long
history of technological evolution, we take what we conceive ourselves
now to be as normative and essential. We project back into the lives of
primitive man, of our own racial ancestors, or of our grandfathers, the
habits and requirements which we acknowledge in ourselves today and we
conceive the men of the past to have been driven forward on the ways of
progress by the identical discontent that would presumably beset
ourselves if we were to be suddenly carried back to their scale and
manner of existence.

Sec. 3. Whatever else may be thought of it, there is at least this to be
said for the cult of historic homesickness to which reference has just
been made: it happens to be at one with modern ethnology and history in
suggesting that earlier cultures were on the whole not less content and
self-satisfied in their condition than our own. It is primitive man, not
the modern, who is slow to move and is satisfied, as a matter of course,
with the manner of life in which he fancies his people to have lived
from time immemorial. Change in early social groups is tragic when it is
not insensible. It comes through conquest and enslavement by outsiders
or through stress of the dread of these, or by gradual adaptation of
custom to failing environmental resources or to increasing wealth.
Assent to change is in general grudging or