When sight and hearing gather their varying information, there must be some central unity to which both report.How could there be any statement of difference unless all sense-impressions appeared before a common identity able to take the sum of all?
This there must be, as there is a centre to a circle; the sense-impressions converging from every point of occurrence will be as lines striking from a circumference to what will be a true centre of perception as being a veritable unity.
If this centre were to break into separate points- so that the sense-impressions fell upon the two ends of a line- then, either it must reknit itself to unity and identity, perhaps at the mid-point of the line, or all remains unrelated, every end receiving the report of its particular field exactly as you and I have our distinct sense experiences.
Suppose the sense-object be such a unity as a face: all the points of observation must be brought together in one visual total, as is obvious since there could be no panorama of great expanses unless the detail were compressed to the capacity of the pupils.
Much more must this be true in the case of thoughts, partless entities as they are, impinging upon the centre of consciousness which [to receive them] must itself be void of part.
Either this or, supposing the centre of consciousness to be a thing of quantity and extension, the sensible object will coincide with it point by point of their co-expansion so that any given point in the faculty will perceive solely what coincides with it in the object: and thus nothing in us could perceive any thing as a whole.
This cannot be: the faculty entire must be a unity; no such dividing is possible; this is no matter in which we can think of equal sections coinciding; the centre of consciousness has no such relation of equality with any sensible object.The only possible ratio of divisibility would be that of the number of diverse elements in the impinging sensation: are we then to suppose that each part of the soul, and every part of each part, will have perception? Or will the part of the parts have none? That is impossible: every part, then, has perception; the [hypothetical] magnitude, of soul and each part of soul, is infinitely divisible; there will therefore be in each part an infinite number of perceptions of the object, and therefore an infinitude of representations of it at our centre of consciousness.
If the sentient be a material entity sensation could only be of the order of seal-impressions struck by a ring on wax, in this case by sensible objects on the blood or on the intervenient air.
If, at this, the impression is like one made in liquids- as would be reasonable- it will be confused and wavering as upon water, and there can be no memory.If the impressions are permanent, then either no fresh ones can be stamped upon the occupied ground- and there can be no change of sensations- or, others being made, the former will be obliterated; and all record of the past is done away with.
If memory implies fresh sensations imposed upon former ones, the earlier not barring their way, the soul cannot be a material entity.
7.We come to the same result by examining the sense of pain.We say there is pain in the finger: the trouble is doubtless in the finger, but our opponents must admit that the sensation of the pain is in the centre of consciousness.The suffering member is one thing, the sense of suffering is another: how does this happen?
By transmission, they will say: the psychic pneuma [= the semi-material principle of life] stationed at the finger suffers first; and stage by stage the trouble is passed on until at last it reaches the centre of consciousness.
But on this theory, there must be a sensation in the spot first suffering pain, and another sensation at a second point of the line of transmission, another in the third and so on; many sensations, in fact an unlimited series, to deal with one pain; and at the last moment the centre of consciousness has the sensation of all these sensations and of its own sensation to boot.Or to be exact, these serial sensations will not be of the pain in the finger: the sensation next in succession to the suffering finger will be of pain at the joint, a third will tell of a pain still higher up: there will be a series of separate pains: The centre of consciousness will not feel the pain seated at the finger, but only that impinging upon itself: it will know this alone, ignore the rest and so have no notion that the finger is in pain.
Thus: Transmission would not give sensation of the actual condition at the affected spot: it is not in the nature of body that where one part suffers there should be knowledge in another part;for body is a magnitude, and the parts of every magnitude are distinct parts; therefore we need, as the sentient, something of a nature to be identical to itself at any and every spot; this property can belong only to some other form of being than body.
8.It can be shown also that the intellectual act would similarly be impossible if the soul were any form of body.