Dr. De Wette, the famous German Biblical critic, returning home one evening between nine and ten o’clock, was surprised, upon arriving opposite the house in which he resided, to see a bright light burning in his study.  In fact, he was rather more than surprised; for he distinctly remembered to have extinguished the candles when he went out, an hour or two previously, locked the door, and put the key in his pocket, which, upon feeling for it, was still there.  Pausing a moment to wonder by what means and for what purpose any one could have entered the room, he perceived the shadow of a person apparently occupied about something in a remote corner.  Supposing it to be a burglar employed in rifling his trunk, he was upon the point of alarming the police, when the man advanced to the window, into full view, as if for the purpose of looking out into the street. It was De Wette himself!—­the scholar, author, professor,—­his height, size, figure, stoop,—­his head, his face, his features, eyes, mouth, nose, chin, every one,—­skullcap, study-gown, neck-tie, all, everything:  there was no mistaking him, no deception whatever:  there stood Dr. De Wette in his own library, and he out in the street:—­why, he must be somebody else! The Doctor instinctively grasped his body with his hands, and tried himself with the psychological tests of self-consciousness and identity, doubtful, if he could believe his senses and black were not white, that he longer existed his former self, and stood, perplexed, bewildered, and confounded, gazing at his other likeness looking out of the window.  Upon the person’s retiring from the window, which occurred in a few moments, De Wette resolved not to dispute the possession of his study with the other Doctor before morning, and ringing at the door of a house opposite, where an acquaintance resided, he asked permission to remain over night.

The chamber occupied by him commanded a full view of the interior of his library, and from the window he could see his other self engaged in study and meditation, now walking up and down the room, immersed in thought, now sitting down at the desk to write, now rising to search for a volume among the book-shelves, and imitating in all respects the peculiar habits of the great Doctor engaged at work and busy with cogitations.  At length, when the cathedral clock had finished striking through first four and then eleven strokes, as German clocks are wont to do an hour before twelve, De Wette Number Two manifested signs of retiring to rest,—­took out his watch, the identical large gold one the other Doctor in the other chamber felt sure was at that moment safe in his waistcoat-pocket, and wound it up, removed a portion of his clothing, came to the window, closed the curtains, and in a few moments the light disappeared.  De Wette Number One, waiting a little time until convinced that Number Two had disposed himself to sleep, retired also his-self to bed, wondering very much what all this could mean.