e
points, as in many others, she benefited me as much by keeping me right
where I was right, as by leading me to new truths, and ridding me of
errors. My great readiness and eagerness to learn from everybody, and to
make room in my opinions for every new acquisition by adjusting the old
and the new to one another, might, but for her steadying influence, have
seduced me into modifying my early opinions too much. She was in nothing
more valuable to my mental development than by her just measure of the
relative importance of different considerations, which often protected
me from allowing to truths I had only recently learnt to see, a more
important place in my thoughts than was properly their due.

The _Liberty_ is likely to survive longer than anything else that I have
written (with the possible exception of the _Logic_), because the
conjunction of her mind with mine has rendered it a kind of philosophic
text-book of a single truth, which the changes progressively taking
place in modern society tend to bring out into ever stronger relief: the
importance, to man and society of a large variety in types of character,
and of giving full freedom to human nature to expand itself in
innumerable and conflicting directions. Nothing can better show how deep
are the foundations of this truth, than the great impression made by the
exposition of it at a time which, to superficial observation, did not
seem to stand much in need of such a lesson. The fears we expressed,
lest the inevitable growth of social equality and of the government of
public opinion, should impose on mankind an oppressive yoke of
uniformity in opinion and practice, might easily have appeared
chimerical to those who looked more at present facts than at tendencies;
for the gradual revolution that is taking place in society and
institutions has, thus far, been decidedly favourable to the development
of new opinions, and has procured for them a much more unprejudiced
hearing than they previously met with. But this is a feature belonging
to periods of transition, when old notions and feelings have been
unsettled, and no new doctrines have yet succeeded to their ascendancy.
At such times people of any mental activity, having given up their old
beliefs, and not feeling quite sure that those they still retain can
stand unmodified, listen eagerly to new opinions. But this state of
things is necessarily transitory: some particular body of doctrine in
time rallies the majori