But, some may say, _That Spiritual Substances are so_. I answer: That Spirits must be either Material, or Immaterial: for, it is impossible for a thing to be between Body and no Body. Others may say, _There may be a Substance, that is not a Natural Substance; but, some sort of Substance that is far more pure than the purest Natural Substance_. I answer: Were it never so pure, it would be in the List or Circle of Body: and certainly, the purest Substance, must have the Properties of Body, as, to be divisible, and capable to be united and compounded; and being divisible and compoundable, it would have the same Properties that grosser Parts have: but, if there be any difference, certainly the purest Substance would be more apt to divide and unite, or compound, than the grosser sort. But, as to those sorts of Substance, which some Learned Men have imagined; in my opinion, they are but the same sort of Substance that the Vulgar call, _Thoughts_, and I name, the _Rational Parts_; which, questionless, are as truly Body, as the grossest Parts in Nature: but, most Human Creatures are so troubled with the Thoughts of Dissolving, and Dis-uniting, that they turn Fancies and Imaginations, into Spirits, or Spiritual Substances; as if all the other Parts of their Bodies, should become Rational Parts; that is, that all their Parts should turn into such Parts as Thoughts, which I name, the _Rational Parts_. But that Opinion is impossible: for, Nature cannot alter the nature of any Part; nor can any Part alter its own Nature; neither can the Rational Parts be divided from the Sensitive and Inanimate Parts, by reason those Three sorts constitute but one Body, as being Parts of one Body. But, put the case that the Rational Parts might divide and subsist without the Sensitive and Inanimate Parts; yet, as I said, they must of necessity have the Properties and Nature of a Body, which is, to be divisible, and capable to be united, and so to be Parts: for, it is impossible for a Body, were it the most pure, to be indivisible. CHAP. II. Of an IMMATERIAL. I Cannot conceive how an Immaterial can be in Nature: for, first, An Immaterial cannot, in my opinion, be naturally created; nor can I conceive how an Immaterial can produce particular Immaterial Souls, Spirits, or the like. Wherefore, an Immaterial, in my opinion, must be some uncreated Being; which can be no other than GOD alone. Wherefore, Created Spirits, and Spiritual Souls, are some other thing than an Immaterial: for surely, if there were any other Immaterial Beings, besides the Omnipotent God, those would be so near the Divine Essence of God, as to be petty gods; and numerous petty gods, would, almost, make the Power of an Infinite God. But, God is Omnipotent, and only God. CHAP. III. Whether an Immaterial be Perceivable.