I felt, as every one else must have felt who reflected upon the
expression in question, that it was fallacious till this was done.
When I first began to write "Life and Habit" I did not believe it
could be done, but when I had gone right up to the end, as it were,
of my cu de sac, I saw the path which led straight to the point I
had despaired of reaching--I mean I saw that personality could not
be broken as between generations, without also breaking it between
the years, days, and moments of a man's life. What differentiates
"Life and Habit" from the "Principles of Psychology" is the
prominence given to continued personal identity, and hence to bona
fide memory, as between successive generations; but surely this
makes the two books differ widely.

Ideas can be changed to almost any extent in almost any direction,
if the change is brought about gradually and in accordance with the
rules of all development. As in music we may take almost any
possible discord with pleasing effect if we have prepared and
resolved it rightly, so our ideas will outlive and outgrow almost
any modification which is approached and quitted in such a way as to
fuse the old and new harmoniously. Words are to ideas what the
fairy invisible cloak was to the prince who wore it--only that the
prince was seen till he put on the cloak, whereas ideas are unseen
until they don the robe of words which reveals them to us; the
words, however, and the ideas, should be such as fit each other and
stick to one another in our minds as soon as they are brought
together, or the ideas will fly off, and leave the words void of
that spirit by the aid of which alone they can become transmuted
into physical action and shape material things with their own
impress. Whether a discord is too violent or no, depends on what we