r industries, and no one can compute the fortunes
we lost. Through scientific knowledge, we have begun to utilize these
by-products. Some of the greatest of modern industries, and the fortunes
which have grown out of them, are the result.

Selling and advertising used to be done partly by tradition and partly by
instinct, so called. To-day, while they have, perhaps, not been reduced to
exact sciences, they are based more and more upon exact knowledge, so that
merchandizing has become less and less a gamble and more and more a
satisfaction.

Since, through scientific knowledge, man has wrought such miracles in
agriculture, construction, education, commerce, industry, finance,
medicine, war, mining, and practically all of his other activities, it is
time he applied the same scientific methods to that without which all
these wonderful things would never have been executed, namely, his mind
and soul.

SCIENTIFIC KNOWLEDGE OF SELF

In Part One of this book we have attempted to show the benefits which
follow upon self-knowledge as to vocation. But this is only one phase,
after all, of your life and activity. Obedience to the injunction, "know
thyself," will help, also, to solve many of the hard problems you meet in
education, social life, religion, morality, and family relations. The man
who, through character analysis, has a scientific knowledge of himself,
has therein a valuable guide to self-development and self-improvement. He
knows which qualities to cultivate and which to restrain. He knows what
situations and associations to avoid so that his frailties and weaknesses
will handicap him as little as possible.

SCIENTIFIC KNOWLEDGE IN EMPLOYMENT

In Part Two we have shown briefly the application of knowledge of human
nature to the selection, assignment and management of employees. In
common with so many other important matters, this has been left in the
past very largely to superstitious traditions, guesswork, random,
hit-or-miss methods, chicanery, and so-called intuition. Now, for the sake
of his profits, and also for the sake of the fellow human beings with whom
he deals, the wise employer is seeking for and, in many cases, using exact
knowledge.

SCIENTIFIC KNOWLEDGE IN PERSUASION

In Part Three we have referred to the use of character analysis in
persuasion. Without this knowledge, it is the most natural thing in the
world for the man who seeks to persuade others to present to them the
arguments and suggest