§ 46. Substance (subject) cannot be known. Only accidents (predicates) can be known. Substance is a mere Idea, not an object. Pure reason, however, wrongly wants to know the subject of every predicate. Every subject, however, is a predicate for yet another subject, and so on as far as our knowledge of predicates extends. We can never know an ultimate subject or absolute substance. We seem to have an "ego", though, which is a thinking subject for our thoughts. The "ego", however, is not known. It is only a conceptless feeling of an existence and a representation of something that is related to all thinking.