propounds a question and then proceeds to answer it in his own way.  He makes it appear plausible, assuring his hearers it is the only way, and they agree because they do not have enough other facts at their command to refute it.  They are unable, as we say, to see the situation in several aspects.  The mistakes in reasoning which children make have a similar basis.  The child reaches for the moon, reasoning—­“Here is something bright; I can touch most bright things; therefore, I can touch this.”  His reasoning is fallacious because he does not have all the facts.  This condition is paralleled in the class-room when students make what are shamefacedly looked back upon as miserable blunders.  When one of these fiascos occurs the cause can many times be referred to the fact that the student did not have enough facts at his command.  Speaking broadly, the most effective reasoning in a field can be done by one who has had the most extensive experiences in that field.  If one had complete acquaintance with all facts, one would have perfect conditions for reasoning.  Thus we see that effectiveness in reasoning demands an extensive array of facts.  Accordingly, in your courses of study you must read with avidity.  When you are given a list of readings in a course, some of which are required and some optional, read both sets, and every new fact thus secured will make you better able to reason in the field.

But good reasoning demands more than mere quantity of ideas.  The ideas must conform to certain qualitative standards before they may be effectively employed in reasoning.  They must arise with promptness, in an orderly manner, pertinent to the matter in hand, and they must be clear.  In securing promptness of association on the part of your ideas, employ the methods described in the chapter on memory.  Make many logical associations with clearness and repetition.  In order to insure the rise of ideas in an orderly manner, pay attention to the manner in which you acquire them.

Remember, things will be recalled as they were impressed, so the value of your ideas in reasoning will depend upon the manner in which you make original impressions.  A further characteristic of serviceable ideas is clarity.  Ideas are sometimes described as “clear” in opposition to “muddy.”  You know what is meant by these distinctions, and you may be assured that one cause for your failures in reasoning is that your ideas are not clear.  This manifests itself in inability to make clear statements and to comprehend clearly.  The latter condition is easily illustrated.  When you began the study of geometry you faced a multitude of new terms; we call them technical terms, such as projection, scalene, theory of limits.  These had to be clearly understood before you could reason in the subject.  And when, in the progress of your study, you experienced difficulty in reasoning out problems, it was very likely due to the fact that you did not master the technical terms, and as soon as you encountered the difficulties of the course, you failed because your foundation laying did not involve the acquisition of clear ideas.  Examine your difficulties in reasoning subjects and if you find them traceable to vagueness of ideas, take steps to clarify them.