I have the impression that by these last considerations we have approached nearer to a comprehension of the supremacy of the pleasure-principle, but we have not attained to an explanation of those cases which are opposed to it. Let us therefore go a step further. Such external excitations as are strong enough to break through the barrier against stimuli we call traumatic. In my opinion the concept of trauma involves such a relationship to an otherwise efficacious barrier. An occurrence such as an external trauma will undoubtedly provoke a very extensive disturbance in the workings of the energy of the organism, and will set in motion every kind of protective measure. But the pleasure-principle is to begin with put out of action here. The flooding of the psychic apparatus with large masses of stimuli can no longer be prevented: on the contrary, another task presents itself—to bring the stimulus under control, to ‘bind’ in the psyche the stimulus mass that has broken its way in, so as to bring about a discharge of it. Probably the specific discomfort of bodily pain is the result of some local breaking through of the barrier against stimuli. From this point in the periphery there stream to the central psychic apparatus continual excitations such as would otherwise come only from within.[13] What are we to expect as the reaction of the psychic life to this invasion? From all sides the ‘charging energy’ is called on in order to create all round the breach correspondingly high ‘charges’ of energy. An immense ‘counter-charge’ is set up, in favour of which all the other psychic systems are impoverished, so that a wide-spread paralysis or diminution of other psychic activity follows. We endeavour to learn from examples such as these to base our metapsychological conjectures on such prototypes. Thus from this behaviour we draw the conclusion that even a highly charged system is able to receive new energy streaming in, to convert it into a ‘quiescent charge’, thus to ‘bind’ it psychically. The more intense is the intrinsic quiescent charge the greater is its binding force: and conversely the lower the charge of the system the less capable is it of receiving the energy that streams in, and so the more violent are the consequences when the barrier against stimuli is broken through. It is not a valid objection to this view that the intensifying of the charges round the place of irruption could be much more simply explained as the direct action of the oncoming mass of excitation. If that were so, the psychic apparatus would merely undergo an increase of its energy charges, and the paralysing character of pain, with the impoverishment of all the other systems, would remain without explanation. Nor do the very violent discharge effects of pain invalidate our explanation, for they happen in a reflex manner, that is to say, they follow without the interposition of the psychic apparatus. The indefinite nature of all the discussions that we term