AUTHOR'S PREFACE
In the realm of mental phenomena, experiment and measurement have hitherto been chiefly limited in application to sense perception and to the time relations of mental processes. By means of the following investigations we have tried to go a step farther into the workings of the mind and to submit to an experimental and quantitative treatment the manifestations of memory. The term, memory, is to be taken here in its broadest sense, including Learning, Retention, Association and Reproduction.
The principal objections which, as a matter of course, rise against the possibility of such a treatment are discussed in detail in the text and in part have been made objects of investigation. I may therefore ask those who are not already convinced a priori of the impossibility of such an attempt to postpone their decision about its practicability.
The author will be pardoned the publication of preliminary results in view of the difficulty of the subject investigated and the time-consuming character of the tests. Justice demands that the many defects due to incompleteness shall not be raised as objections against such results. The tests were all made upon myself and have primarily only individual significance. Naturally they will not reflect exclusively mere idiosyncrasies of my mental organisation; if the absolute values found are throughout only individual, yet many a relation of general validity will be found in the relation of these numbers to each other or in the relations of the relations. But where this is the case and where it is not, I can hope to decide only after finishing the further and comparative experiments with which I am occupied.
