Psycho-physiological factors such as excitement, absent-mindedness, distraction of attention, obviously provide very little in the way of explanation. They are mere phrases; they are screens, and we should not be deterred from looking behind them. The question is rather what has here called forth the excitement or the particular diversion of attention. The influence of sound-values, resemblances between words, and common associations connecting certain words, must also be recognized as important. They facilitate the slip by pointing out a path for it to take. But if there is a path before me does it necessarily follow that I must go along it? I also require a motive to determining my choice and, further, some force to propel me forward. These sound-values and word associations are, therefore, just like the bodily conditions, the facilitating causes of slips of the tongue, and cannot provide the real explanation of them. Consider for a moment the enormous majority of cases in which the words I am using in my speech are not deranged on account of sound-resemblance to other words, intimate associations with opposite meanings, or with expressions in common use. It yet remains to suppose, with the philosopher Wundt, that a slip of the tongue arises when the tendency to associations gains an ascendance over the original intention owing to bodily fatigue. This would be quite plausible if experience did not controvert it by the fact that in a number of cases the bodily, and in another large group the associative, predisposing causes are absent. Particularly interesting to me, however, is your next question, namely, by what means the two mutually disturbing tendencies may be ascertained. You probably do not suspect how portentous this question is. You will agree that one of these tendencies, the one which is interfered with, is always unmistakable; the person who commits the slip knows it and acknowledges it. Doubt and hesitation only arise in regard to the other, what we have called the interfering, tendency. Now we have already heard, and you will certainly not have forgotten, that in a certain number of cases this other tendency is equally plain. It is evident in the result of the slip if only we have the courage to let the slip speak for itself. The President who said the opposite of what he meant—it is clear that he wishes to open the session, but equally clear that he would also like to close it. That is so plain that it needs no interpreting. But in the other cases, in which the interfering tendency merely distorts the original without itself coming to full expression,—how can the interfering tendency be detected in the distortion?