of the situation
as it first confronts us. In logically elaborating a suggestion,
as we have already seen, we trace out the bearings of a given
situation. We expand it; we see what it _implies_, what it
means. Thus, if we came, for example, to a meeting that
had been scheduled, and found no one present, we might
have several solutions arise in our minds. The meeting, we
might suppose, had been transferred to another room. If
that were the case, there would probably be some notice
posted. In all cases of deductive elaboration, we go through
what might be called the If-Then process. If _such-and-such_ is
the case, then _such-and-such_ will follow. We can then verify
our suggested solution to a problem, by going back to the
facts, to see whether they correspond with the implications
of our suggestion. We may, to take another example, think
that a man who enters our office is an insurance agent, or a
book solicitor who had said he would call upon us at a definite
date. If such is the case, he will say such-and-such things.
If he does say them, then our suggestion is seen to be correct.
The advantages of developing a suggestion include the fact
that some link in the logical chain may bear a more obvious
relation to our problem than did the undeveloped suggestion
itself.

The systematic sciences consist of such sets of principles
so related that any single term implies certain others, which
imply certain others and so on _ad infinitum_.

After the facts have been elaborated, the generalization,
however plausible it may seem, must be subjected to experimental
corroboration. That is, if a suggestion is found
through local elaboration to mean _A, B, C_, then the situation
must be reexamined to see if the facts to be found tally with
the facts deduced. In the case cited, the suggestion that the
man who entered the room was the insurance agent we expected
would be verified if he immediately broached the subject
and the fact, say, of a previous conversation. In the case
of disease, if the illness is typhoid, we shall find certain specific
conditions in the patient. If these are found, the suggestion
of typhoid is verified.

The _reliability_ of generalizations made by this scientific
procedure varies according to several factors. It varies, in
the first place, according to the correspondence of the predictions
made on the basis of the generalization, with subsequent
events. The reason we say the law of gravitation holds
t