Page:The Psychology of Shakespeare.pdf/281

264 This imputation of insanity to smother truth is as old as the time when it was replied to by the great apostle of truth, in the very spirit of Isabella's appeal: "I am not mad most noble Festus, but speak forth the words of truth and soberness." The test which the Duke applies is the only one valid in regard to the reason, although it is opposed to Locke's theory, that madmen reason right on wrong premises. But the right statement of the premises is a great part of the reasoning process: the dependency of one premise on another being duly set forth, the conclusion follows as a matter of course. Hence it follows, that although it may be needful to apply other tests to ascertain the soundness of other functions of the mind, that of the reason, strictly so called, must ever be estimated by the due sequence of ideas, the "dependency of thing on thing."