The same happens concerning the operations of the mind, viz. thinking, reasoning, fearing, &c., which we concluding not to subsist of themselves, nor apprehending how they can belong to body, or be produced by it, we are apt to think these the actions of some other SUBSTANCE, which we call SPIRIT; whereby yet it is evident that, having no other idea or notion of matter, but something wherein those many sensible qualities which affect our senses do subsist; by supposing a substance wherein thinking, knowing, doubting, and a power of moving, &c., do subsist, we have as clear a notion of the substance of spirit, as we have of body; the one being supposed to be (without knowing what it is) the SUBSTRATUM to those simple ideas we have from without; and the other supposed (with a like ignorance of what it is) to be the SUBSTRATUM to those operations we experiment in ourselves within. It is plain then, that the idea of CORPOREAL SUBSTANCE in matter is as remote from our conceptions and apprehensions, as that of SPIRITUAL SUBSTANCE, or spirit: and therefore, from our not having any notion of the substance of spirit, we can no more conclude its non-existence, than we can, for the same reason, deny the existence of body; it being as rational to affirm there is no body, because we have no clear and distinct idea of the substance of matter, as to say there is no spirit, because we have no clear and distinct idea of the substance of a spirit. 6. Our ideas of particular Sorts of Substances.