of
the mob, the crimes of a lynching party, and the deeds of collective
righteousness performed by our humane and religious societies.

It would be impossible, of course, within the limits of this little
volume, to give even the main results in so many great chapters of
this ambitious and growing science. I shall not attempt that; but the
rather select from the various departments certain outstanding results
and principles. From these as elevations the reader may see the
mountains on the horizon, so to speak, which at his leisure, and with
better guides, he may explore. The choice of materials from so rich a
store has depended also, as the preface states, on the writer's
individual judgment, and it is quite probable that no one will find
the matters altogether wisely chosen. All the great departments now
thus briefly described, however, are represented in the following
chapters.

CHAPTER II.

WHAT OUR MINDS HAVE IN COMMON--INTROSPECTIVE PSYCHOLOGY.

Of all the sources now indicated from which the psychologist may draw,
that of so-called Introspective Psychology--the actual reports of what
we find going on in our minds from time to time--is the most
important. This is true for two great reasons, which make Psychology
different from all the other sciences. The first claim which the
introspective method has upon us arises from the fact that it is only
by it that we can examine the mind directly, and get its events in
their purity. Each of us knows himself better than he knows any one
else. So this department, in which we deal each with his own
consciousness at first hand, is more reliable, if free from error,
than any of those spheres in which we examine other persons, so long
as we are dealing with the psychology of the individual. The second
reason that this method of procedure is most important is found in the
fact that all the other departments of psychology--and with them all
the other sciences--have to use introspection, after all, to make sure
of the results which they get by other methods. For example, the
natural scientist, the botanist, let us say, and the physical
scientist, the electrician, say, can not observe the plants or the
electric sparks without really using his introspection upon what is
before him. The light from the plant has to go into his brain and
leave a certain effect in his mind, and then he has to use
introspection to report what he sees. The astronomer who has bad eyes
can not o