What we have here described as the emergence of an individual's intellectual consciousness from the original, purely volitional condition of the soul is nothing but a replica of a greater process through which mankind as a whole, or more exactly Western mankind, has gone in the course of its historical development. Man was not always the 'brain-thinker' he is to-day.7 Directly the separation of the nerve system was completed, and thereby the full clarity of the brain-bound consciousness achieved, man began to concern himself with science in the modern sense. To understand why this science became restricted to one-eyed, colour-blind observation we need only apply to the human sense system, in particular, what we have learnt concerning man's threefold being. Sharply distinguished by their respective modes of functioning though they are, the three bodily systems are each spread out through the whole body and are thus to be found everywhere adjacent to each other. Hence, the corresponding three states of consciousness, the sleeping, dreaming and waking, are also everywhere adjacent and woven into one another. It is the predominance of one or other which imparts a particular quality of soul to one or other region of the body. This is clearly shown within the realm of sense activity, itself the most conscious part of the human being. It is sufficient to compare, say, the senses of sight and smell, and to notice in what different degree we are conscious of the impressions they convey, and how differently the corresponding elements of conception, feeling and willing are blended in each. We never turn away as instinctively from objectionable colour arrangement as from an unpleasant smell. How small a part, on the other hand, do the representations of odours play in our recollection of past experiences, compared with those of sight.8 The same is valid in descending measure for all other senses. Of all senses, the sense of sight has in greatest measure the qualities of a 'conceptual sense'. The experiences which it brings, and these alone, were suitable as a basis for the new science, and even so a further limitation was necessary. For in spite of the special quality of the sense of sight, it is still not free from certain elements of feeling and will - that is, from elements with the character of dream or sleep. The first plays a part in our perception of colour; the second, in observing the forms and perspective ordering of objects we look at.