The other cases of translocation of our sensations are equally easily interpreted without supposing any 'projection'
from a centre at which they are originally perceived.Unfortunately the details are intricate; and what I say now can only be made fully clear when we come to the next chapter.We shall then see that we are constantly selecting certain of our sensations as realities and degrading others to the status of signs of these.When we get one of the signs we think of the reality signified; and the strange thing is that then the reality (which need not be itself a sensation at all at the time, but only an idea) is so interesting that it acquires an hallucinatory strength, which may even eclipse that of the relatively uninteresting sign and entirely divert our attention from the latter.Thus the sensations to which our joints give rise when they rotate are signs of what, through a large number of other sensations, tactile and optical, we have come to know as the movement of the whole limb.This movement of the whole limb is what we think of when the joint's nerves are excited in that way; and its place is so much more important than the joint's place that our sense of the latter is taken up, so to speak, into our perception of the former, and the sensation of the movement seems to diffuse itself into our very fingers and toes.But by abstracting our attention from the suggestion of the entire extremity we can perfectly well perceive the same sensation as if it were concentrated in one spot.We can identify it with a differently located tactile and visual image of 'the joint' itself.
Just so when we feel the tip of our cane against the ground.The peculiar sort of movement of the hand (impossible in one direction, but free in every other) which we experience when the tip touches 'the ground,' is a sign to us of the visual and tactile object which we already know under that name.We think of 'the ground'
as being there and giving us the sensation of this kind of movement.The sensation, we say, comes from the ground.The ground's place seems to be its place; although at the same time, and for very similar practical reasons, we think of another optical and tactile object, 'the hand' namely, and consider that its place also must be the place of our sensation.
In other words, we take an object or sensible content A, and confounding it with another object otherwise known, B, or with two objects otherwise known, B and C, we identify its place with their places.But in all this there is no 'projecting ' (such as the extradition-philosophers talk of) of A out of an original place; no primitive location which it first occupied, away from these other sensations, has to be contradicted;
no natural ' centre,' from which it is expelled, exists.That would imply that A aboriginally came to us in definite local relations with other sensations, for to be out of B and C is to be in local relation with them as much as to be in them is so.But it was no more out of B and C than it was in them when it first came to us.It simply had nothing to do with them.To say that we feel a sensation's seat to be 'in the brain' or 'against the eye'
or 'under the skin' is to say as much about it and to deal with it in as non-primitive a way as to say that it is a mile off.These are all secondary perceptions, ways of defining the sensation's seat per aliud.They involve numberless associations, identifications, and imaginations, and admit a great deal of vacillation and uncertainty in the result.
I conclude, then, that there is no truth in the 'eccentric projection' theory.It is due to the confused assumption that the bodily processes which cause a sensation must also be its seat.
But sensations have no seat in this sense.They become seats for each other, as fast as experience associates them together; but that violates no primitive seat possessed by any one of them.And though our sensations cannot then so analyze and talk of themselves, yet at their very first appearance quite as much as at any later date are they cognizant of all those qualities which we end by extracting and conceiving under the names of objectivity, exteriority, and extent.It is surely subjectivity and inferiority which are the notions latest acquired by the human mind.
Some persons will say that we never have a really simple object or content.My definition of sensation does not require the simplicity to be absolutely, but only relatively, extreme.It is worth while in passing, however, to warn the reader against a couple of inferences that are often made.One is that because we gradually learn to analyze so many qualities we ought to conclude that there are no really indecomposable feelings in the mind.The other is that because the processes that produce our sensations are multiple, the sensations regarded as subjective facts must also be compound.To take an example, to a child the taste of lemonade comes at first as a simple quality.He later learns both that many stimuli and many nerves are involved in the exhibition of this taste to his wind, and he also learns to perceive separately the sourness, the coolness, the sweet, the lemon aroma, etc., and the several degrees of strength of each and all of these things, --
