This seems so entirely comprehensible and also irrefutable. It is perhaps not very interesting or not so much so as we expected. Let us look at this explanation of errors more closely. The various conditions which have been cited as necessary for the occurrence of these phenomena are not all similar in kind. Illness and disorders of the circulation afford a physiological basis for an affection of the normal functions; excitement, tiredness, and distraction are conditions of a different kind which could be described as psycho-physiological. These last could easily be converted into a theory. Fatigue, as well as distraction, and perhaps also general excitement, cause a dissipation of the attention from which it may follow that the act in question has insufficient attention devoted to it. It can then very easily be disturbed and inexactly performed. Slight illness or a change in the distribution of blood in the central organ of the nervous system can have the same effect, by these conditions affecting the determining factor, the distribution of attention, in a similar way. In all cases it would be a question of the effects of a disturbance of the attention from organic or psychical causes. But all this doesn’t seem to promise much of interest for a psycho-analytic investigation. We might feel tempted to give up the topic. To be sure, a closer inspection of the facts shows that they are not all in accord with the ‘attention’ theory of errors of this sort, or at least that not everything can be directly deduced from it. We find that such errors and such forgetfulness also take place when people are not fatigued or excited, but are in every way in their normal condition; unless, just because of the errors, we were subsequently to attribute to them a condition of excitement which they themselves did not acknowledge. Nor can the matter be quite so simple as that the successful performance of an act will be ensured by an intensification of attention, or endangered by a diminution of it. For a great number of actions may be carried out in a purely automatic way with very little attention and yet quite successfully. In walking, a man may perhaps scarcely know where he is going but keep to the right road and stop at his destination without having gone astray. At least, this is what usually happens. A practised pianist strikes the right notes without thinking of them. He may of course also make an occasional mistake, but if automatic playing increased the danger of errors the virtuoso, whose constant practice has made his playing entirely automatic, would be the most exposed to this danger. Yet we see, on the contrary, that many acts are most successfully carried out when they are not the objects of particularly concentrated attention, and that mistakes may occur just on occasions when one is most eager to be accurate, that is, when a distraction of the necessary attention is most certainly not present.