Strictly speaking, this is a phenomenon of the disorganization rather than of the organization of the mind. Third, the impressions received when the mind is alert and reacts with energy upon the stimuli will survive longer in their integrity than those which are received in moments of mental relaxation. Some minds do not habitually react with vigour, and do not therefore have much retentiveness. Some react with much more vigour to certain classes of stimuli than to others, and their retentiveness varies accordingly. A mind that is habitually lax and slothful finds it especially difficult to revive distinct and definite images of experience. Its mental reproductions of experience are a sort of blur. Very often, certainly, in cases of poor recollection the fault is to be found in the character of the original experience. There was not sufficient alertness; the mental reaction upon the stimulus was not vigorous; the impression upon the brain was indistinct and indefinite. Such an experience it is impossible to revive clearly because the experience itself lacked clearness. We may state it as a law that the vividness of the recalled experience will vary with the vividness of the original experience. It cannot be too much emphasized that in cases of bad memory the deficiency in all probability is in the state of the attention in the original experience. Because of failure here many public speakers find themselves deficient in vivid mental images and effective illustrative material. Fourth, each impression seems to be modified by, or in some measure to blend with, or somehow to be linked up with other impressions, both those which precede and those which follow it. It may be true, therefore, that no impression once definitely made is entirely lost from the brain, except by the process of disorganization referred to above. It may, however, survive not as a distinct impression, the physical basis for a revival of a distinguishable individual image, but as a factor in a total composite impression. This linking of impressions with one another and their reciprocal modification is doubtless the physical counterpart of the "association of ideas," and of the formation of con-
