To illustrate this relationship, I once used a simile which I will now repeat because I know of no better one as substitute. Let us suppose that some dark night I go past a lonely spot and am there assaulted by a rascal who takes my watch and purse; and then, since I did not see the face of the robber clearly, I make my complaint at the nearest police station in the following words: "Loneliness and darkness have just robbed me of my valuables." The police commissioner could then say to me: "You seem to hold an unjustifiably extreme mechanistic conception. Let us rather state the case as follows: Under cover of darkness, and favored by the loneliness, an unknown robber seized your valuables. The essential task in your case seems to me to be to discover the robber. Perhaps we can then take his booty from him again." Such psycho-physiological moments as excitement, absent-mindedness and distracted attention, are obviously of small assistance to us for the purpose of explanation. They are mere phrases, screens behind which we will not be deterred from looking. The question is rather what in such cases has caused the excitement, the particular diversion of attention. The influence of syllable sounds, word resemblances and the customary associations which words arouse should also be recognized as having significance. They facilitate the tongue slip by pointing the path which it can take. But if I have a path before me, does that fact as a matter of course determine that I will follow it? After all, I must have a stimulus to make me decide for it, and, in addition, a force which carries me forward on this path. These sound and word relationships therefore serve also only to facilitate the tongue slip, just as the bodily dispositions facilitate them; they cannot give the explanation for the word itself. Just consider, for example, the fact that in an enormously large number of cases, my lecturing is not disturbed by the fact that the words which I use recall others by their sound resemblance, that they are intimately associated with their opposites, or arouse common associations. We might add here the observation of the philosopher Wundt, that slips of the tongue occur when, in consequence of bodily fatigue, the tendency to association gains the upper hand over the intended speech. This would sound very plausible if it were not contradicted by experiences which proved that from one series of cases of tongue-slips bodily stimuli were absent, and from another, the association stimuli were absent.