The Doctor is very little happier in reasoning upon _immateriality_. He says, by way of illustrating his argument, "that it is possible to infinite power to create an immaterial cogitative substance, endued with a power of beginning motion, and with a liberty of will or choice." Again, "that immaterial substances are not impossible; or, that a substance immaterial is not a contradictory notion. Now, whoever asserts that it is contradictory, must affirm that whatever is not matter is nothing; and that, to say any thing exists which is not matter, is saying that there exists something which is nothing, which in other words is plainly this,--that whatever we have not an idea of, is nothing, and impossible to be." It could, I am apt to believe, never have entered into any reasonable mind that a thing was impossible because he could have no idea of it:--many things, on the contrary, are possible, of which we have not the most slender notion: but it does not, I presume, flow consecutively out of this admission, that therefore every thing is, which is not impossible. Doctor Clarke then, rather begs the question on this occasion. In the schools it is never considered requisite to prove a negative; indeed, this is ranked by logicians amongst those things impossible to be, but it is considered of the highest importance to soundness of argument, to establish the affirmative by the most conclusive reasoning. Taking this for granted, we will apply the doctor's own reasoning. He says, "Nothing is that of which every thing, can truly be affirmed. So that the idea of nothing, if I may so speak, is absolutely the negative of all ideas; the idea, therefore, either of a finite or infinite nothing is a contradiction in terms." To affirm, of a thing with truth, it must be necessary to be acquainted with that thing. To have ideas, as we have already proved, it is necessary to have perceptions; to have perceptions, it is requisite to have sensations; to have sensations, requires organs. An idea cannot be, and not be, at the same moment: the idea of substance, it will scarcely be denied, is that of a thing solid, real, according to Dryden; capable of supporting accidents, according to Watts; something of which we can say that it is, according to Davies; body, corporeal nature, according to Newton; the idea of immaterial, according to Hooker, is incorporeal. How then am I to understand immaterial substance? Is it not, according to these definitions, that which cannot couple together? If a thing be immaterial, it cannot be a substance; if a substance, it cannot be immaterial: those I apprehend will not have many ideas, who do not see this is a complete negative of all ideas. If, therefore, on the outset, the doctor cannot find words, by which he can convey the idea of that of which he is so desirous to prove the existence, by what chain of reasoning does he flatter himself that he is to be understood? He will