calls here an electro-magnetic disturbance is light, so that it is really light that the optic nerve perceives objectively when subject to electrical stimulus. The doctrine of specific energy appears to be nowhere more firmly based than in the case of the ear: nowhere also has the real existence of the thing perceived become more probable. We will not insist on these facts, because they will be found stated and exhaustively discussed in a recent work.[1] We will only remark that the sensations here spoken of are not images perceived by us outside our body, but rather affections localized within the body. Now it results from the nature and use of our body, as we shall see, that each of its so-called sensory elements has its own real action, which must be of the same kind as its virtual action on the external objects which it usually perceives; and thus we can understand how it is that each of the sensory nerves appears to vibrate according to a fixed manner of sensation. But to elucidate this point we must consider the nature of affection. Thus we are led to the third and last argument which we have to examine.
This third argument is drawn from the fact that we pass by insensible degrees from the representative state which occupies space, to the affective state which appears to be unextended.
- ↑ Schwarz, Das Wahrnehmungsproblem, Leipzig, 1892, pp. 313 and seq.
