A similar experience is reported by Dr. Hans Sachs of Vienna: “I always carry two keys with me, one for the door of my office and one for my residence. They are not by any means easily interchanged, as the office key is at least three times as big as my house key. Besides, I carry the first in my trouser pocket and the other in my vest pocket. Yet it often happened that I noticed on reaching the door that while ascending the stairs I had taken out the wrong key. I decided to undertake a statistical examination; as I was daily in about the same emotional state when I stood before both doors, I thought that the interchanging of the two keys must show a regular tendency, if they were differently determined psychically. Observation of later occurrences showed that I regularly took out my house key before the office door. Only on one occasion was this reversed: I came home tired, knowing that I would find there a guest. I made an attempt to unlock the door with the, naturally too big, office key.” (_b_) At a certain time twice a day for six years I was accustomed to wait for admission before a door in the second story of the same house, and during this long period of time it happened twice (within a short interval) that I climbed a story higher. On the first of these occasions I was in an ambitious day-dream, which allowed me to “mount always higher and higher.” In fact, at that time I heard the door in question open as I put my foot on the first step of the third flight. On the other occasion I again went too far “engrossed in thought.” As soon as I became aware of it, I turned back and sought to snatch the dominating fantasy; I found that I was irritated over a criticism of my works, in which the reproach was made that I “always went too far,” which I replaced by the less respectful expression “climbed too high.” (_c_) For many years a reflex hammer and a tuning-fork lay side by side on my desk. One day I hurried off at the close of my office hours, as I wished to catch a certain train, and, despite broad daylight, put the tuning-fork in my coat pocket in place of the reflex hammer. My attention was called to the mistake through the weight of the object drawing down my pocket. Any one unaccustomed to reflect on such slight occurrences would without hesitation explain the faulty action by the hurry of the moment, and excuse it. In spite of that, I preferred to ask myself why I took the tuning-fork instead of the hammer. The haste could just as well have been a motive for carrying out the action properly in order not to waste time over the correction.