as its condition. A man must disengage in thought, a tree, for instance, from the thought of all perception of it, and then he must believe in its existence thus disengaged. If he has not disengaged, in his mind, the tree from its perception (from its present perception, if the tree be before him; from its remembered perception, if it be not before him), he cannot believe in the existence of the tree disengaged from its perception; for the tree is not disengaged from its perception. But unless he believes in the existence of the tree disengaged from its perception, he does not believe in the independent existence of the tree, in the existence of the tree per se. Now, can the mind by any effort effect this disengagement? The thing is an absolute impossibility. The condition on which the belief hinges cannot be purified, and consequently the belief itself cannot be entertained.
People have, then, no belief in the independent existence of matter; that is, in the existence of matter entirely denuded of perception. This point being proved, what becomes of Dr Reid's appeal to this belief in support of matter's independent existence? It has not only no force, it has no meaning. This second tactic is invincible. Scepticism and idealism are perfectly in the right when they refuse to accept as the guarantee of independent matter a belief which itself has no manner of existence. How can they be vanquished by an appeal to a nonentity?
A question may here be raised. If the belief in
