ct the psychological spaces between words and word forms. The
general drift seizes upon those individual sound variations that help to
preserve the morphological balance or to lead to the new balance that
the language is striving for.

I would suggest, then, that phonetic change is compacted of at least
three basic strands: (1) A general drift in one direction, concerning
the nature of which we know almost nothing but which may be suspected to
be of prevailingly dynamic character (tendencies, e.g., to greater or
less stress, greater or less voicing of elements); (2) A readjusting
tendency which aims to preserve or restore the fundamental phonetic
pattern of the language; (3) A preservative tendency which sets in when
a too serious morphological unsettlement is threatened by the main
drift. I do not imagine for a moment that it is always possible to
separate these strands or that this purely schematic statement does
justice to the complex forces that guide the phonetic drift. The
phonetic pattern of a language is not invariable, but it changes far
less readily than the sounds that compose it. Every phonetic element
that it possesses may change radically and yet the pattern remain
unaffected. It would be absurd to claim that our present English pattern
is identical with the old Indo-European one, yet it is impressive to
note that even at this late day the English series of initial
consonants:

_p_ _t_ _k_
_b_ _d_ _g_
_f_ _th_ _h_

corresponds point for point to the Sanskrit series:

_b_ _d_ _g_
_bh_ _dh_ _gh_
_p_ _t_ _k_

The relation between phonetic pattern and individual sound is roughly
parallel to that which obtains between the morphologic type of a
language and one of its specific morphological features. Both phonetic
pattern and fundamental type are exceedingly conservative, all
superficial appearances to the contrary notwithstanding. Which is more
so we cannot say. I suspect that they hang together in a way that we
cannot at present quite understand.

If all the phonetic changes brought about by the phonetic drift were
allowed to stand, it is probable that most languages would present such
irregularities of morphological contour as to lose touch with their
formal ground-plan. Sound changes work mechanically. Hence they are
likely to affect a whole morphological group here--this does not
matter--, only part of a morphological group there--and this may be
disturbing. Thus, the old Anglo-Saxon par