ver, indeed, a strain is thrown on the attention, the
heart and organs of respiration are put under pressure also in their
effort to assist the attention in manipulating the problem; and these
organic fluctuations are felt as pleasure and pain. The strains thrown
on the attention of primitive man were connected with his struggle
for life; and not only in the actual encounter with men and animals
did emotion run high, but the memory and anticipation of conflict
reinstated the emotional conditions in those periods when he was
meditating future conflicts and preparing his bows and arrows, traps
and poisons. The problem of invention, the reflective and scientific
side of his life, was suffused with interest, because the manufacture
of the weapon was, psychologically speaking, a part of the fight.

This type of interest, originating in the hunt, remains dominant
in the mind down to the present time. Once constructed to take an
interest in the hunting problem, it takes an interest in any problem
whatever. Not only do hunting and fighting and all competitive
games--which are of precisely the same psychological pattern as the
hunt and fight--remain of perennial interest, but all the useful
occupations are interesting in just the degree that this pattern is
preserved. The man of science works at problems and uses his ingenuity
in making an engine in the laboratory in the same way that primitive
man used his mind in making a trap. So long as the problem is
present, the interest is sustained; and the interest ceases when
the problematical is removed. Consequently, all modern occupations
of the hunting pattern--scientific investigation, law, medicine,
the organization of business, trade speculation, and the arts and
crafts--are interesting as a game; while those occupations into which
the division of labor enters to the degree that the workman is not
attempting to control a problem, and in which the same acts are
repeated an indefinite number of times, lose interest and become
extremely irksome.

This means that the brain acts pleasurably on the principle it was
made up to act on in the most primitive times, and the rest is a
burden. There is no brain change, but the social changes have been
momentous; and the brain of each generation is brought into contact
with new traditions, inhibitions, copies, obligations, problems, so
that the run of attention and content of consciousness are different.
Social suggestion works marvels in t