Mental states of every kind, - sensations, feelings, ideas, - which were at one time present in consciousness and then have disappeared from it, have not with their disappearance absolutely ceased to exist.

No matter how thoroughly a person may have learned the Greek alphabet, he will never be in a condition to repeat it backwards without further training.

The musician writes for the orchestra what his inner voice sings to him; the painter rarely relies without disadvantage solely upon the images which his inner eye presents to him; nature gives him his forms, study governs his combinations of them.

A poem is learned by heart and then not again repeated. We will suppose that after a half year it has been forgotten: no effort of recollection is able to call it back again into consciousness.

Meanwhile the fact that the connection with the activity of memory in ordinary life is for the moment lost is of less importance than the reverse, namely, that this connection with the complications and fluctuations of life is necessarily still a too close one.

Series of syllables which have been learned by heart, forgotten, and learned anew must be similar as to their inner conditions at the times when they can be recited.

Humans more easily remember or learn items when they are studied a few times over a long period of time (spaced presentation), rather than studied repeatedly in a short period of time.