ld not consist merely of
fumbling about in a vague hope of hitting upon some solution. It must
be a systematic search, guided by carefully chosen ideas. For example,
"if the clock on the mantle-piece has stopped, and we have no idea how
to make it go again, but mildly shake it in the hope that something
will happen to set it going, we are merely fumbling. But if, on moving
the clock gently so as to set the pendulum in motion, we hear it
wobbling about irregularly, and at the same time observe that there is
no ticking of any kind, we come to the conclusion that the pendulum has
somehow or other escaped the little catch that connects it with the
mechanism, we have been really thinking. From the fact that the
pendulum wobbles irregularly, we infer that it has lost its proper
catch. From the fact that there is no ticking, we infer the same thing,
for even when there is something wrong with the clock that will prevent
it from going permanently, if the pendulum is set in motion by force
from without it will tick for a few seconds before it comes to rest
again. The important point to observe is that there must be inference.
This is always indicated by the word _therefore_ or its equivalent. If
you reach a conclusion without having to use or at any rate to imply a
_therefore_, you may take it for granted that you have not been really
thinking, but only jumping to conclusions."

This process of putting facts in the form of judgments and drawing
inferences, may be likened to a court-room scene where arguments are
presented to the judge. As each bit of evidence is submitted, it is
subjected to the test of its applicability to the situation or to
similar situations in the past. It is rigidly examined and nothing is
accepted as a candidate for the solution until it is found by trial (of
course, in imagination) to be pertinent to the situation.

The third stage of the reasoning process comes when some plan which has
been suggested as a possible solution of the difficulty proves
effective, and we make the decision; the arguments support or overthrow
each other, adding to and eliminating various considerations until
finally only one course appears possible. As we said before, the
solution comes inevitably, as represented by the word _therefore_.
Little active work on our part is necessary, for if we have gone
through these other phases properly the decision will make itself. You
cannot make a wrong decision if you have the facts befor