3. Natural Science and Anthroposophy

This thinking forms, as it were, the content of consciousness when we have trained this consciousness as I have just indicated. But then, when we move in this thinking, we can remember the concept of being, the concept of reality that we have appropriated from the outer world, especially from the scientifically researched outer world as presented to us by natural science. On the one hand, we take this concept of reality. It need not be particularly clear at first; it can simply be the idea that takes root in us through our direct and scientific contact with the external world. We take this concept, this idea of reality on the one hand, and on the other hand we take what we consciously experience when we engage in free thinking, then something occurs in our soul – yes, I could call it a basic law, I could call it an experience – something occurs to which one must inwardly confess to oneself by saying: I think, but I am not in thinking, that is, I am not as I have come to know existence in the outer world. And the momentous sentence appears before us: I think, therefore I am not.