The Science of Human Nature | Page 8

of getting its facts is by observation and experiment.
SUMMARY. Science is systematic, related knowledge. Each science
has a particular field which it attempts to explore and describe. The
field of psychology is the study of sensitivity, action, and
consciousness, or briefly, human behavior. Its main problems are
development, heredity, instincts, habits, sensation, memory, thinking,
and individual differences. Its method is observation and experiment,
the same as in all other sciences.
CLASS EXERCISES
1. Make out a list of things about human nature which you would like
to know. Paste your list in the front of this book, and as you find your
questions answered in this book, or in other books which you may read,
check them off. At the end of the course, note how many remain
unanswered. Find out whether those not answered can be answered at
the present time.
2. Does everything you do have a cause? What kind of cause?
3. Human nature is shown in human action. Human action consists in
muscular contraction. What makes a muscle contract?

4. Plan an experiment the object of which shall be to learn something
about yourself.
5. Enumerate the professions and occupations in which a knowledge of
some aspect of human nature would be valuable. State in what way it
would be valuable.
6. Make a list of facts concerning a child, which a teacher ought to
know.
7. Make a complete outline of Chapter I.
REFERENCES FOR CLASS READING
MÜNSTERBERG: Psychology, General and Applied, Chapters I, II,
and V.
PILLSBURY: Essentials of Psychology, Chapter I.
PYLE: The Outlines of Educational Psychology, Chapter I.
TITCHENER: A Beginner's Psychology, Chapter I.
CHAPTER II
DEVELOPMENT OF THE RACE AND OF THE INDIVIDUAL
=Racial Development.= The purpose of this chapter is to make some
inquiry concerning the origin of the race and of the individual. In doing
this, it is necessary for us first of all to fix in our minds the idea of
causality. According to the view of all modern science, everything has
a cause. Nothing is uncaused. One event is the result of other previous
events, and is in turn the cause of other events that follow. Yesterday
flowed into to-day, and to-day flows into to-morrow. The world as it
exists to-day is the result of the world as it existed yesterday. This is
true not only of the inorganic world--the world of physics and
chemistry--but it is true of living things as well. The animals and plants
that exist to-day are the descendants of others that lived before. There is

probably an unbroken line of descent from the first life that existed on
the earth to the living forms of to-day.
Not only does the law of causality hold true in the case of our bodies,
but of our minds as well. Our minds have doubtless developed from
simpler minds just as our bodies have developed from simpler bodies.
That different grades and types of minds are to be found among the
various classes of animals now upon the earth, no one can doubt, for
the different forms certainly show different degrees of mentality.
According to the evidence of those scientists who have studied the
remains of animals found in the earth's crust, there is a gradual
development of animal forms shown in successive epochs. In the very
oldest parts of the earth's crust, the remains of animal life found are
very simple. In later formations, the remains show an animal life more
complex. The highest forms of animals, the mammals, are found only
in the more recent formations. The remains of man are found only in
the latest formations.
Putting these two facts together--(1) that the higher types of mind are
found to-day only in the higher types of animals, and (2) that a gradual
development of animal forms is shown by the remains in the earth's
crust--the conclusion is forced upon us that mind has passed through
many stages of development from the appearance of life upon the earth
to the present time. Among the lower forms of animals to-day one sees
evidence of very simple minds. In amoebas, worms, insects, and fishes,
mind is very simple. In birds, it is higher. In mammals, it is higher still.
Among the highest mammals below man, we see manifestations of
mind somewhat like our own. These grades of mentality shown in the
animals of to-day represent the steps in the development of mind in the
animals of the past.
We cannot here go into the proof of the doctrine of development. For
this proof, the reader must be referred to zoölogy. One further point,
however, may be noted. If it is difficult for the reader to conceive of the
development of mind on the earth similar to the development of
animals in the past, let him think of