But from Marcus Donatus we read the following case of still more melancholy interest; another illustration of your question, dear Castaly: “Vicentinus believed himself too large to pass one of his doorways. To dispel this illusion, it was resolved by his physician that he should be _dragged through this aperture by force_. This erroneous dictate was obeyed; but, as he was forced along, Vicentinus screamed out in agony, that his limbs were fractured, and the flesh torn from his bones. In this dreadful delusion, with terrific imprecations against his murderers, he died.” ABSTRACTION OF INTELLECT. “I love to cope him in these sullen fits, For then he’s full of matter.” AS YOU LIKE IT. ASTR. So that in these cases it is _one faculty only_ which is interrupted, and not the _combined intellect_. But all the faculties _but_ one may be deranged, may they not? EV. Yes. When the patient is insane on all points but one, we term it, “Folie raisonnante.” The very idiot, indeed, is often fond of most exact arrangement. The savage of Aveyron instantly put things in order when they were deranged. White, in his “History of Selborne,” records the propensities of an idiot, who, he says, was a very _Merops-apiaster_, or Bee-bird. Honey-bees, humblebees, and wasps, were his prey: he would seize them, disarm them of their weapons, and suck their bodies for the sake of their honey-bags. Except in this adroitness, he had no understanding. Pinel states the case of a mechanical genius, who became insane, believing _his head to be changed_. Yet he invented mechanism of the most intricate combinations. We are informed, too, of a clergyman, who was ever insane, but when delivering his discourses from the pulpit. I believe some parts of a national establishment were constructed from the plans of one of its inmates, who was to all other intents and purposes a madman. Dr. Uwins once told me, that some of the lines in his biographical work were written by a maniac in the Hoxton Asylum, who was ever aware of the approach of his mania. These lines were thought to be among the best in the work. Nay, idiots will sometimes reason, and work out a syllogism. I think Dr. Conolly relates a story of two, who quarrelled, because each asserted that he was the Holy Ghost; at length, one decided that the other _was_ the Holy Ghost, and that he _could not be, because_ there were not two. From this “folie raisonnante” there is an easy transition to that eccentricity which seems to be a set-off against the _strength of mind_ of the deep thinker. The _permanent_ derangement, however, we term _insanity_; the _transient, eccentricity_.