III. Thinking as the Instrument of Knowledge

When I observe how a billiard ball, when struck, communicates its motion to another, I remain entirely without influence on the course of this observed process before me. The direction and velocity of the motion of, the second ball is determined by the direction and velocity of the first. As long as I remain a mere spectator, I cannot tell anything about the motion of the second ball until it has happened. It is quite different when I begin to reflect on the content of my observations. The purpose of my reflection is to form concepts of the occurrence. I connect the concept of an elastic ball with certain other concepts of mechanics, and consider the special circumstances which obtain in the instance in question. I try, in other words, to add to the occurrence which takes place without my assistance a second process which takes place in the conceptual sphere. This latter one is dependent on me. This is shown by the fact that I can rest content with the observation, and renounce all search for concepts if I have no need of them. If, however, this need is present, then I am not content until I have established a certain connection among the concepts, ball, elasticity, motion, impact, velocity, etc., so that they apply to the observed process in a definite way. As surely as the occurrence goes on independently of me, so surely is the conceptual process unable to take place without my activity.