But since it is likewise possible that I may find cause, drawn from somewhere else than mere speculative grounds, to hope for an existence of my thinking nature that is self sufficient and persisting through all possible changes of my state, much is still won if, through the free confession of my ignorance, I can nevertheless repel the dogmatic attacks of a speculative opponent, and show him that he can never know more in which to deny my expectations about the nature of my subject than I can in order to hold to them.