It will be probably a surprise to hear that neither the state of sleep nor illness is among the indispensable conditions. A whole number of phenomena of the everyday life of healthy persons, forgetfulness, slips in speaking and in holding things, together with a certain class of mistakes, are due to a psychical mechanism analogous to that of the dream and the other members of this group.

Displacement is the core of the problem, and the most striking of all the dream performances. A thorough investigation of the subject shows that the essential condition of displacement is purely psychological; it is in the nature of a motive. We get on the track by thrashing out experiences which one cannot avoid in the analysis of dreams. I had to break off the relations of my dream thoughts in the analysis of my dream on p.