he subject until he has
found a reason, for it may depend upon facts or principles of which he
is not at the moment informed; but if such is the case, he should
accept the fact tentatively, but make a mental note that it is
something which clearly must have a reason which he is capable of
perceiving, and which he will look up at some future time. In studying
his book he may well make a list of such questions to ask the teacher
or to look up later.

Students must of course proceed in a systematic way, and a student who
has not studied physics cannot be expected to perceive reasons that
depend upon the laws of physics, and yet without a knowledge of physics
he may still perceive that a statement is not of a mere fact, but of
something that must have a reason. To primitive peoples nature was a
closed book. The simplest phenomena were beyond their understanding,
and they, therefore, imagined deities of whose personal activities
these phenomena {14} were supposed to be manifestations. With the
progress of science many phenomena once mysterious and looked upon as
facts have become easily explained. The intelligent student, however,
can generally distinguish between statements of the different kinds
which have been described, and he should constantly endeavor to explain
or seek the reason for new statements by relating them to the body of
knowledge which he has previously gained. Unfortunately, the average
student reads only to accept what is written, whether fact, conclusion,
or opinion, perhaps memorizing it verbatim under the impression that by
so doing he is learning; he does not examine or reflect upon it, and
often even accepts as facts what are explicitly stated to be mere
expressions of opinion. Thus palpable mistakes, or even typographical
errors, which a careful student should detect at once, are often
accepted and believed. It is for this reason that it is so easy to
deceive most people, at least for part of the time. They do not think
for themselves, and all that is necessary to make them believe what you
say is in some way to get them to think you are an authority.

(_d_) REGARDING FACTS WHICH HE DOES NOT THEN INVESTIGATE THE REASON
FOR, HE SHOULD ASK How THEY ARE ASCERTAINED.--This will {15} draw his
attention to methods of observation and experiment, or to the technique
of the subject. How, for instance, is it ascertained that New York is
90 miles from Philadelphia, or that the sun is ninety-two mil