But if the joint-feelings are directions and extents, standing in relation to each other, the task of association in interpreting their import in eye- or skin-terms is a good deal simplified. Let the movement _bc_, of a certain joint, derive its absolute space-value from the cutaneous feeling it is always capable of engendering; then the longer movement _abcd_ of the same joint will be judged to have a greater space-value, even though it may never have wholly merged with a skin-experience. So of differences of direction: so much joint-difference = so much skin-difference; therefore, more joint-difference = more skin-difference. _In fact, the joint-feeling can excellently serve as a map on a reduced scale, of a reality which the imagination can identify at its pleasure with this or that sensible extension simultaneously known in some other way._ When the joint-feeling in itself acquires an emotional interest,--which happens whenever the joint is inflamed and painful,--the secondary suggestions fail to arise, and the movement is felt where it is, and in its intrinsic scale of magnitude.[195] The localization of the joint-feeling in a space simultaneously known otherwise (i.e. to eye or skin), is what is commonly called the _extradition or eccentric projection of the feeling_. In the preceding chapter I said a good deal on this subject; but we must now see a little more closely just what happens in this instance of it. The content of the joint-feeling, to begin with, is an object, and _is_ in itself a place. For it to be _placed_, say _in the elbow_, the elbow as seen or handled must already have become another object for the mind, and with its place as thus known, the place which the joint-feeling fills must coalesce. That the latter should be felt 'in the elbow' is therefore a 'projection' of it into the place of another object as much as its being felt in the finger-tip or at the end of a cane can be. But when we say 'projection' we generally have in our mind the notion of a _there_ as contrasted with a _here_. What is the _here_ when we say that the joint-feeling is _there_? The 'here' seems to be the spot which the mind has chosen for its own post of observation, usually some place within the head, but sometimes within the throat or breast--not a rigorously fixed spot, but a region from any portion of which it may send forth its various acts of attention. Extradition from either of _these_ regions is the common law under which we perceive the whereabouts of the north star, of our own voice, of the contact of our teeth with each other, of the tip of our finger, of the point of our cane on the ground, or of a movement in our elbow-joint.