In this essay Professor Bergson made several contributions to our knowledge of dreams. He showed, in the first place, that dreaming is not so unlike the ordinary process of perception as had been hitherto supposed. Both use sense impressions as crude material to be molded and defined by the aid of memory images. Here, too, he set forth the idea, which he, so far as I know, was the first to formulate, that sleep is a state of disinterestedness, a theory which has since been adopted by several psychologists. In this address, also, was brought into consideration for the first time the idea that the self may go through different degrees of tension--a theory referred to in his _Matter and Memory_. Its chief interest for the general reader will, however, lie in the explanation it gives him of the cause of some of his familiar dreams. He may by practice become the interpreter of his own visions and so come to an understanding of the vagaries of that mysterious and inseparable companion, his dream-self. EDWIN E. SLOSSON. NEW YORK CITY, FEBRUARY 10, 1914. DREAMS The subject which I have to discuss here is so complex, it raises so many questions of all kinds, difficult, obscure, some psychological, others physiological and metaphysical; in order to be treated in a complete manner it requires such a long development--and we have so little space, that I shall ask your permission to dispense with all preamble, to set aside unessentials, and to go at once to the heart of the question. A dream is this. I perceive objects and there is nothing there. I see men; I seem to speak to them and I hear what they answer; there is no one there and I have not spoken. It is all _as if_ real things and real persons were there, then on waking all has disappeared, both persons and things. How does this happen? But, first, is it true that there is nothing there? I mean, is there not presented a certain sense material to our eyes, to our ears, to our touch, etc., during sleep as well as during waking?