1. We receive this idea from touch.
The idea of solidity we receive by our touch: and it arises from the resistance
which we find in body to the entrance of any other body into the place it possesses, till it has left it. There is no
idea which we receive more constantly from sensation than solidity. Whether we move or rest, in what posture
soever we are, we always feel something under us that support us, and hinders our further sinking downwards;
and the bodies which we daily handle make us perceive that, whilst they remain between them, they do, by an
insurmountable force, hinder the approach of the parts of our hands that press them. That which thus hinders the
approach of two bodies, when they are moved one towards another, I call solidity. I will not dispute whether this
acceptation of the word solid be nearer to its original signification than that which mathematicians use it in. It
suffices that I think the common notion of solidity will allow, if not justify, this use of it; but if any one think it
better to call it impenetrability, he has my consent. Only I have thought the term solidity the more proper to
express this idea, not only because of its vulgar use in that sense, but also because it carries something more of
positive in it than impenetrability; which is negative, and is perhaps more a consequence of solidity, than solidity
itself. This, of all other, seems the idea most intimately connected with, and essential to body; so as nowhere else
to be found or imagined, but only in matter. And though our senses take no notice of it, but in masses of matter, of
a bulk sufficient to cause a sensation in us: yet the mind, having once got this idea from such grosser sensible
bodies, traces it further, and considers it, as well as figure, in the minutest particle of matter that can exist; and
finds it inseparably inherent in body, wherever or however modified.
