AUTHOR'S PREFACE   TO  SECOND
EDITION

WHEN I viras asked some years since by the publisher of
this work to undertake its revision, I felt some hesita¬
tion in complying with his request. The first edition
of the Lectures appeared thirty years ago ; and during that
time there had not only been a great advance in experimental
psychology, but my own scientific knowledge and convictions
had been considerably increased and modified. Thirty years
ago the science was no more than a programme for the future.
Except in psychophysics, where Fechner had just broken
ground, everything remained still to do ; and distrust and sus¬
picion met the investigator at every turn. As for myself, I had
had but little experience in the difficult work of psychological
analysis, which the gradual development of the experimental
methods has done so much to further; and set about my task
with more zeal than discretion. So that for years before the
appearance of the first edition of my Physiological Psychology,
in which I took up the same problem with more modesty and
caution, I had learned to look upon the Lectures as wild oats
of my youthful days, which I would gladly have forgotten.
But, unfortunately, hypotheses and views represented in them
would every now and again be confused with or counted among
my more mature convictions.

That I have resolved to undertake a second edition despite
these somewhat discouraging facts, and in preference to the
more grateful task of writing a new work of similar character,
is due in the main to two circumstances.    In the first place, I