15 
of existence or force in this external world, which is not our- 
selves. But I have a right to demand from a disputant both 
a definition of matter and a proof of its existence. It appears 
to me that this existence is either an unproved inference from 
the experience of resistance, or is a delusion attached to a 
word of our infancy. Why cannot I close my hand upon a 
brick ? The answer of a child is, because the brick is there, 
inactive and inert there, a piece of stuff which is doing 
nothing but just lying there : this is the notion of sluggish 
quiescent matter. The thinker perceives that he is prevented 
from closing his hand by force perpetually in action there, 
and that the brick is what it is by virtue of intense cohesion, 
and other resistances that defeat his pressure and the force of 
his will. Thus he gets the compound notion of matter 
having its seat in space, and of force having its seat in the 
matter. 
But what need is there of the matter ? Why may not the 
forces have their seats in space ? How can you construct a 
demonstration of the presence of this matter ? 
You appeal first to the evidence of our senses. But we 
are all agreed that our sight and hearing can teach us nothing 
about forces, resistances, and motions, except through the 
interpreter touch ; that the telegrams which reach the mind 
by sight and hearing are rapidly translated into nothing but 
the memory of touch. Now touch teaches us absolutely 
nothing but resistances , except lessons of pleasure and pain 
that may be here left out of consideration. Thus the evi- 
dence of our senses comes to nothing more than the con- 
sciousness and the memory of forces which resist our own 
force of volition. 
You say that this table is a geometrical locus of material 
