therefore less subject to such unconceiveable affections; and however, it can be no wayes known to our faculties or cognitive powers, that they have any such specifical property or affection. 3. As it is not any way manifest to any of our senses, nor can be proved by any sound deductions of reason, so it cannot be manifested to be any innate notion shining from the Intellect it self, and we ought not to take adventitious ones instead of those that are innate, nor fictitious ones for either, but to make a due distinction of each of them one from another. 4. Neither is indiscerpibility a proper difference of a spiritual substance from a corporeal one, because the visible species of things do in the air intersect one another, and suffer not discerpibility: and that these are bodies is manifest, because they affect the senses; and therefore that which is a property of some bodies cannot be the proper difference to distinguish a spirit from a body. 5. This is only an arbitrary and feigned supposition, and cannot be proved either by the testimony of any of the senses, by sound reason, or innate notions; and what is or cannot be proved by some of these (according to his own position) ought to be rejected. And therefore as indiscerpibility is no proper difference of a spirit from a body, no more is penetrability, which can no more be in a spiritual substance, than either in discreet quantity one can be two, or two one, or in continuate quantity one inch can be two, or two can become one. D^r _Glisson_ from his much admired _Suarius_ the great Weaver of fruitless Cobwebs, hath devised another difference of spirit from body which he thus layeth down, as we give it in this English. “I assign (he saith) a twofold difference betwixt the substance of matter and that of spirits. The first is taken from the substantial (_à substantiali materiæ mole_) heap or weight of the matter. For I (he saith) besides the actual and accidental extension, do attribute to the matter this substantial heap or weight which is denied to spirits. But the sign of this heap or weight is, that if the matter in the same space be duplicated, triplicated, or centuplicated, that it will be made more dense twofold, threefold, or an hundred fold. And concludeth thus: I answer (he saith) that matter and spirit in this do agree betwixt themselves, that they both are finite, and from thence that they have this common, that neither of them can reduce themselves into a littleness that is infinite, or into an infinite magnitude. Therefore the difference betwixt them doth not consist in this; but in this, that a spirit whether it be contracted or dilated, is not made more dense or rare; but on the contrary, matter, whether it be contracted or expanded, is made more dense, or more rare.” To which we return this responsion. 1. It is usual with men, when by their wills and fancies they would maintain an opinion that is weak and groundless, finding they cannot