Finally, another department, the newest of all, investigates the action of minds when they are thrown together in crowds.

The animals herd, the insects swarm, most creatures live in companies; they are gregarious, and man no less is social in his nature.

So there is a psychology of herds, crowds, mobs, etc., all put under the heading of "Social Psychology." It asks the question, What new phases of the mind do we find when individuals unite in common action ?--or, on the other hand, when they are artificially separated?
We now have with all this a fairly complete idea of what The Story of the Mind should include, when it is all told.

Many men are spending their lives each at one or two of these great questions.

But it is only as the results are all brought together in a consistent view of that wonderful thing, the mind, that we may hope to find out all that it is.