It must not be thought that because we are only dimly aware of the contents of this twilight zone therefore the individual elements lack definiteness and positive reality. To do so is to confuse the awareness of a certain something with that something itself. To so think would be like thinking that, because we do not distinctly recognize objects in the darkness, therefore they are but shadowy forms without substance. When, in states of abstraction or hypnosis, the ideas of this fringe of attention are recalled, as often is easily done, they are remembered as _very definite, real, conscious elements_, and the memory of them is as vivid as that of most thoughts. That these marginal ideas are not “vivid” at the time of their occurrence means simply that they are not in such dynamic relations with the whole content of consciousness as to be the focus of awareness or attention. What sort of relations are requisite for “awareness” is an unsolved problem. It seems to be a matter not only of synthesis but of dynamic relations within the synthesis. However that may be, outside that dynamic synthesis which we distinguish as the focus of attention we can at certain moments recognize or recall to memory (whether through technical devices or not) a number of different conscious states. These may be roughly classified as follows: 1: Visual, auditory, and other sensory impressions to which we are not giving attention—(e. g., the striking of a clock; the sound of horses passing in the street; voices from the next room; coenæsthetic and other sensations of the body. 2: The secondary sensory images of which I spoke in the last lecture as taking part in perception. 3: Associative memories and thoughts pertaining to the ideas in the focus of attention. 4: Secondary independent trains of thought not related to those in the focus of attention. (As when we are doing one thing or listening to conversation and thinking of something else. Very likely, however, what appear to be secondary trains of thought are often only alternating trains. I have, however, a considerable collection of data showing such concomitant secondary trains in certain subjects (cf. Lecture VI). Such a train can be demonstrated to be a precisely differentiated “stream” of consciousness in absent-minded conditions, where it may constitute a veritable doubling of consciousness.