6. It is easy to show that if the Soul were a corporeal entity, there could be no sense-perception, no mental act, no knowledge, no moral excellence, nothing of all that is noble.
There can be no perception without a unitary percipient whose identity enables it to grasp an object as an entirety.
The several senses will each be the entrance point of many diverse perceptions; in any one object there may be many characteristics; any one organ may be the channel of a group of objects, as for instance a face is known not by a special sense for separate features, nose, eyes; etc., but by one sense observing all in one act.
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.