Locke in his celebrated work, the "Essay Concerning Human Understanding" has clearly stated the difference between the meaning of these several terms. He says: "Memory is the power to revive again in our minds those ideas which after imprinting, have disappeared, or have been laid aside out of sight--when an idea again recurs without the operation of the like object on the external sensory, it is _remembrance_; if it be sought after by the mind, and with pain and endeavor found, and brought again into view, it is _recollection_." Fuller says, commenting on this: "Memory is the power of reproducing in the mind former impressions, or percepts. Remembrance and Recollection are the exercise of that power, the former being involuntary or spontaneous, the latter volitional. We remember because we cannot help it but we recollect only through positive effort. The act of remembering, taken by itself, is involuntary. In other words, when the mind remembers without having tried to remember, it acts spontaneously. Thus it may be said, in the narrow, contrasted senses of the two terms, that we remember by chance, but recollect by intention, and if the endeavor be successful that which is reproduced becomes, by the very effort to bring it forth, more firmly intrenched in the mind than ever." But the New Psychology makes a little different distinction from that of Locke, as given above. It uses the word memory not only in his sense of "The power to revive, etc.," but also in the sense of the activities of the mind which tend to receive and store away the various impressions of the senses, and the ideas conceived by the mind, to the end that they may be reproduced voluntarily, or involuntarily, thereafter. The distinction between remembrance and recollection, as made by Locke, is adopted as correct by The New Psychology.