Hermann Ebbinghaus

“ Often, even after years, mental states once present in consciousness return to it with apparent spontaneity and without any act of the will; that is, they are reproduced involuntarily. ”

“ The burnt child shuns the fire, and the dog which has been beaten runs from the whip, after a single vivid experience. People in whom we are interested we may see daily and yet not be able to recall the color of their hair or of their eyes.
Under ordinary circumstances, indeed, frequent repetitions are indispensable in order to make possible the reproduction of a given content. Vocabularies, discourses, and poems of any length cannot be learned by a single repetition even with the greatest concentration of attention on the part of an individual of very great ability. ”

“ How does the disappearance of the ability to reproduce, forgetfulness, depend upon the length of time during which no repetitions have taken place? What proportion does the increase in certainty of reproduction bear to the number of repetitions? ”

“ The vanished mental states give indubitable proof of their continuing existence even if they themselves do not return to consciousness at all, or at least not exactly at the given time. Employment of a certain range of thought facilitates under certain conditions the employment of a similar range of thought, even if the former does not come before the mind directly either in its methods or in its results. The boundless domain of the effect of accumulated experience belongs here. ”

“ If by any chance a way to a deeper penetration into this matter should present itself, surely, considering the significance of memory for all mental phenomena, it should be our wish to enter that path at once. For at the very worst we should prefer to see resignation arise from the failure of earnest investigations rather than from persistent, helpless astonishment in the face of their difficulties. ”

“ Forms and colors are not so importunate; and if they do return, it is with noticeable loss of clearness and certainty. 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. ”

“ Psychology is wont to make the picture rich with anecdote and illustration. But—and this is the main point—even if we particularise our knowledge by a most extended use of illustrative material, everything that we can say retains the indefinite, general, and comparative character of the propositions quoted above. ”

“ To it might be added such a series of propositions known to psychology as the following: “He who learns quickly also forgets quickly,” “Relatively long series of ideas are retained better than relatively short ones,” “Old people forget most quickly the things they learned last,” and the like. ”

“ And not only does this comparison hold good when different individuals are compared with each other, but also when different phases of the existence of the same individual are compared: morning and evening, youth and old age, find him different in this respect. ”

“ Of course the existence of all these deficiencies has its perfectly sufficient basis in the extraordinary difficulty and complexity of the matter. It remains to be proved whether, in spite of the clearest insight into the inadequacy of our knowledge, we shall ever make any actual progress. ”

“ It is with something of a struggle that past states of feeling are realized; when realized, and this is often only through the instrumentality of the movements which accompanied them, they are but pale shadows of themselves. Emotionally true singing is rarer than technically correct singing. ”