of thinking works itself out more or less in word form; that is, if one wants to express it, to teach it, or to convince any one of it. Evidently it directs itself wholly to the outside world. To this extent, this directed or logical thinking is a reality thinking,2 having a real existence for us; that is to say, a thinking which adjusts itself to actual conditions,3 where we, expressed in other words, imitate the succession of objectively real things, so that the images in our mind follow after each other in the same strictly causal succession as the historical events outside of our mind.4
We call this thinking, thinking with directed attention. It has, in addition, the peculiarity that one is tired by it, and that, on this account, it is set into action only for a time. Our whole vital accomplishment, which is so expensive, is adaptation to environment; a part of it is the directed thinking, which, biologically expressed, is nothing but a process of psychic assimilation, which, as in every vital accomplishment, leaves behind a corresponding exhaustion.
The material with which we think is language and speech concept, a thing which has been used from time immemorial as something external, a bridge for thought, and which has a single purpose—that of communication. As long as we think directedly, we think for others and speak to others.5
Speech is originally a system of emotional and imitative sounds—sounds which express terror, fear, anger, love; and sounds which imitate the noises of the elements, the rushing and gurgling of water, the rolling of thunder,
