_The first Sceptical Tactic._ In answer to Dr Reid's appeal, the sceptic or idealist may say, "Doubtless we have a belief in the independent existence of matter; but this belief is not to be trusted. It is an insufficient guarantee for that which it avouches. It does not follow that a thing is true because we instinctively believe it to be true. It does not follow that matter exists because we cannot but believe it to exist. You must prove its existence by a better argument than mere belief."--This mode of meeting the appeal we hold to be pure trifling. We join issue with Dr Reid in maintaining that our nature is not rooted in delusion, and that the primitive convictions of common sense, must be accepted as infallible. If the sceptic admits that we _have_ a natural belief in the independent existence of matter, there is an end to him: Dr Reid's victory is secure. This first tactic is a feeble and mistaken manoeuvre. _The Second Sceptical Tactic._ This position is not so easily turned. The stronghold of the sceptic and idealist is this: they deny the primitive belief to which Dr Reid appeals to be _the fact_. It is not true, they say, that any man believes in the independent existence of matter. And this is perfectly obvious the moment that it is explained. Matter in its _independent_ existence, matter _per se_, is matter disengaged in thought from all perception of it present or remembered. Now, does any man believe in the existence of such matter? Unquestionably not. No man by any possibility can. What the matter is which man really believes in shall be explained when we come to speak of the metaphysical solution of the problem--perhaps sooner. Meanwhile we remark that Dr Reid's appeal to the conviction of common sense in favour of the existence of matter _per se_, is rebutted, and in our opinion triumphantly, by the denial on the part of scepticism and idealism that any such belief exists. Scepticism and idealism not only deny the independent existence of matter, but they deny that any man believes in the independent existence of matter. And in this denial they are most indubitably right. For observe what such a belief requires 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