These, now, are some of the difficulties which confront you at the outset when you begin to take an interest in psycho-analysis. It is probably more than enough for a beginning. If you can overcome their discouraging effect, we will proceed further. SECOND LECTURE THE PSYCHOLOGY OF ERRORS We shall now begin, not with postulates, but with an investigation. For this purpose we shall select certain phenomena which are very frequent, very familiar and much overlooked, and which have nothing to do with illness, since they may be observed in every healthy person. I refer to the errors that everyone commits: as when anyone wishes to say a certain thing but uses the wrong word (‘slip of the tongue’);[2] or when the same sort of mistake is made in writing (‘slip of the pen’),[3] in which case one may or may not notice it; or when anyone reads in print or writing something other than what is actually before him (‘misreading’);[4] or when anyone mis-hears[5] what is said to him, naturally when there is no question of any disease of the auditory sense-organ. Another series of such phenomena are those based on forgetting[6] something temporarily, though not permanently; as, for instance, when anyone cannot think of a name which he knows quite well and is always able to recognize whenever he sees it; or when anyone forgets to carry out some intention, which he afterwards remembers, and has therefore forgotten only for a certain time. This element of transitoriness is lacking in a third class, of which mislaying[7] things so that they cannot be found is an example. This is a kind of forgetfulness which we regard differently from the usual kind; one is amazed or annoyed at it, instead of finding it comprehensible. Allied to this are certain _mistakes_, in which the temporary element is again noticeable, as when one believes something for a time which both before and afterwards one knows to be untrue, and a number of similar manifestations which we know under various names. Some inner relation between all these kinds of occurrences is indicated in German, by the use of the prefix “_ver_” which is common to all the words designating them.[8] These words almost all refer to acts of an unimportant kind, generally temporary and without much significance in life. It is only rarely that anything of the kind, such as the loss of some object, attains any practical importance. For this reason little attention is paid to such happenings and they arouse little feeling.