Accordingly, persuasion cannot be distinguished from conviction subjectively, when the subject has taken something to be true merely as an appearance of his own mind; but the experiment that one makes on the understanding of others, to see if the grounds that are valid for us have the same effect on the reason of others, is a means, though only a subjective one, not for producing conviction, to be sure, but yet for re vealing the merely private validity of the judgment,.e.