III. Thinking in the Service of Apprehending the World

The feeling of having such a firm point caused the founder of modern philosophy, Descartes, to base all human knowing upon the statement, I think, therefore I am. All other things, everything else that happens is there without me; I do not know whether as truth, whether as illusion and dream. There is only one thing I know with altogether unqualified certainty, for I myself bring it to its certain existence: my thinking. Though it may have still another source of its existence, though it may come from God or from somewhere else; that it is there in that sense in which I myself bring it forth, of this I am certain. Descartes had at first no justification for imputing another meaning to his statement. He could only maintain that, within the content of the world I grasp myself in my thinking as within an activity most inherently my own. What the attached therefore I am is supposed to mean has been much disputed. It can mean something, however, on one condition only. The simplest statement I can make about a thing is that it is, that it exists. How then this existence is to be more closely determined cannot be stated right away with respect to anything that comes onto the horizon of my experiences. One must first examine every object in its relationship to others, in order to be able to determine in which sense it can be spoken of as something existing. An occurrence one experiences may be a sum of perceptions, but also a dream, a hallucination, and so on. In short, I cannot say in which sense it exists. This I cannot conclude from the occurrence itself, but rather I will learn this when I look at the occurrence in relation to other things. There again, however, I can know no more than how it stands in relation to these things. My searching first comes onto firm ground when I find an object from which I can derive the sense of its existence out of it itself. This I am myself, however, in that I think, for I give to my existence the definite, self-sustaining content of thinking activity. Now I can take my start from there and ask whether the other things exist in the same or in a different sense.