sensory surface is non-existent for the sense of touch; and a solid
body, impressed upon the palm of the hand, gives rise only to the
notion of the extension of that particular part of the solid which is
in contact with the skin.

Nor is it possible that the idea of outness (in the sense of
discontinuity with the sentient body) could be attained by such a
person; for, as we have seen, every tactile sensation is referred to
a point either of the natural sensory surface itself, or of some
solid in continuity with that surface. Hence it would appear that the
conception of the difference between the Ego and the non-Ego could
not be attained by a man thus situated. His feelings would be his
universe, and his tactile sensations his "moenia mundi." Time would
exist for him as for us, but space would have only two dimensions.

But now remove the paralysis from the motor apparatus, and give the
palm of the hand of our imaginary man perfect freedom to move, so as
to be able to glide in all directions over the bodies with which it is
in contact. Then with the consciousness of that mobility, the notion
of space of three dimensions--which is "_Raum_" or "room" to move with
perfect freedom--is at once given. But the notion that the tactile
surface itself moves, cannot be given by touch alone, which is
competent to testify only to the fact of change of place, not to its
cause. The idea of the motion of the tactile surface could not, in
fact, be attained, unless the idea of change of place were accompanied
by some state of consciousness, which does not exist when the tactile
surface is immoveable. This state of consciousness is what is termed
the muscular sense, and its existence is very easily demonstrable.

Suppose the back of my hand to rest upon a table, and a sovereign to