THE PHYSICAL CONDITIONS OF CONSCIOUSNESS. 507

exhausts the capacities of language in his futile endeavours to express his unutterable sense of a distracted or lost self, and to make the distressing distraction which he feels conceivable to others. They, however, not being able to conceive it in the least, only receive his words as vague expressions of suffering, which they probably think incontinent and exaggerated, and may even pronounce ' hypochoiidriacal,' and pass them by without the patient and discriminating notice which they ought to obtain. The direct and patent evidence that consciousness is divided, the unity of the individual Ego confused and lost, they are unable to apprehend, because their consciousness is whole, and they are thoroughly prepossessed with the psychological assump- tion that consciousness is one and indivisible, not subject to conditions of time and space, and the like. It were strange, were any inconsistency in human thought strange, how persistently we talk of the continuity of consciousness when the truth is that a conscious state is not continuous, but transient. There are so many trains or successions of thought, as we say justly, but there is not the least evidence of an abstract consciousness abiding between these successions ; no more evidence, in fact, than there is of an abstract express train keeping up a continuity between a number of express trains rapidly following one another on the same line. Moreover, the rapidity with which a train of thought passes through the mind is notably very different in different persons, and in the same person at different times different, for example, in youth and in old age, in health and in sickness, in lively and in sluggish temperaments. In that inflamed state of thought and feel- ing which often precedes an attack of acute mania and gives the transient show of an extraordinary mental brilliance, the trains of thought follow one another with great rapidity at express speed ; in the brain-decay of old age they follow one another slowly and creep along sluggishly, the person being notably slow in apprehending, slow in thinking, slow in uttering his thought. In each case the measure of the rapidity is the measure of the duration of consciousness ; which may, after all, be a measurable function, whenever, if ever, we attain to delicate enough means of making the very nice measurements required. How much rather empty rhetorical eloquence has been uttered at different times concerning the rapidity of con- sciousness ! We are challenged to admire the amazing speed with which it traverses the most distant regions of space, passing in the twinkling of an eye from Kamschatka