Voltaire, like many men of genius, was a neurasthenic and his ideas with strong emotional tones tended to become strongly organized and acquire great force. “The orange rind haunts my dreams,” he wrote; “I try not to believe it.... We go to sup with the king and are gay enough sometimes;—the man who fell from the top of a steeple and found the fall through the air soft and said, ‘Good, provided it lasts,’ is not a little as I am.” The emotional complex which so tormented Voltaire that it literally became an obsession was a recurring memory. The experience had been strongly registered and conserved, owing to the emotional tone, but the reason _why_ there was so much emotion, and _why_ it absorbed so many associated ideas into itself and kept recurring would undoubtedly have been found to lie, if we could have probed Voltaire’s mind, in its settings—his previous stormy experiences with Frederick, his knowledge of Frederick’s character, his previous _apprehensions_ of what later actually occurred, and, most probably, self-reproach for his own behavior, _the consequences of which he feared to face_. All this, conserved as neurograms, was set ablaze by the remark and furnished not only the emotion but the material for the content of the complex. These previous experiences, therefore, stood in genetic relation to the latter, excited the emotional reaction of anger, resentment and fear, and prevented the complex from subsiding. The exciting cause for each recurrence of the complex was, of course, some associated stimulus from the environment, or train of thought.