sketchiest theoretical background to it. At the same
time psychologists are extremely self-conscious
about the need for developing comprehensive theo-
ries. They are apt to compare the present state of
their science with that of physics immediately before
Newton. The physicists had then established a great
many low-level correlations between different
physical phenomena, had observed an immense
number of different regular sequences such as those
incorporated in Kepler's laws of planetary motion.
But it needed the theoretical genius of a Newton to
explain the whole range of phenomena by means of a
few simple concepts which could be given mathe-
matical expression, such as the concept of gravita-
tional attraction. Pre-Newtonian physicists had
however the advantage over contemporary experi-
mental psychologists that they did not know they
were waiting for Newton. By contrast the hankering
of psychologists after a comprehensive theory leads
to their surrounding what is in fact a spectacle of
industry and achievement that merits nothing but
intellectual respect by a haze of aspiration which re-
sembles nothing so much as waiting for a theoretical
Godot.

This, however, is only one side of the picture.
There are also those who believe that psychology
does not need to await its Newton, not because, as
might be maintained, the desire for a Newtonian
transformation of psychology is itself misconceived,
but because psychology has already found its New-
ton. In the sharpest contrast with the often unre-
lated and fragmentary work of the experimentalists

-2-