In order to be in a position successfully to change the outer world through the motility, there is required the accumulation of a large sum of experiences in the memory systems as well as a manifold fixation of the relations which are evoked in this memory material by different end-presentations.

We now proceed further with our assumption. The manifold activity of the second system, tentatively sending forth and retracting energy, must on the one hand have full command over all memory material, but on the other hand it would be a superfluous expenditure for it to send to the individual mental paths large quantities of energy which would thus flow off to no purpose, diminishing the quantity available for the transformation of the outer world. In the interests of expediency I therefore postulate that the second system