Unavoidable if space is interpreted as a property of things in themselves. The mere, but empirically determined, consciousness of my own existence proves the existence of objects in space outside me. I am conscious of my own existence in time. All determination of time presupposes something permanent in perception. The game played by idealism has been turned against itself.
Inner experience is itself possible only mediately, and only through outer experience.
The representation 'I' is not an intuition , it is an intellectual representation of the spontaneity of the thinking person. The necessity of existence can never be known from concepts, but always only from connection with that which is perceived. It is not the existence of substances that we can know necessarily, only the existence of their state in accordance with the law of causality. Nothing happens through blind chance. No necessity in nature is blind, but always conditioned and therefore intelligible necessity.