When we say what we "think," we mean that we exercise the faculties whereby we compare and contrast certain things with other things, observing and noting their points of difference and agreement, then classifying them in accordance with these observed agreements and differences. In thinking we tend to classify the multitude of impressions received from the outside world,[Pg 11] arranging thousands of objects into one general class, and other thousands into other general classes, and then sub-dividing these classes, until finally we have found mental pigeon-holes for every conceivable idea or impression. We then begin to make inferences and deductions regarding these ideas or impressions, working from the known to the unknown, from particulars to generalities, or from generalities to particulars, as the case may be.