3. He tells us that all substance has dimensions, that is, length, breadth and depth, but all has not impenetrability, and boldly saith: It is not the Characteristical of a body to have dimensions, but to be impenetrable; to which we answer. It is strongly asserted by learned _Helmont_, that by the ultimate strength of nature, bodies do sometimes penetrate themselves and one another, and to that purpose he giveth convincing examples, and concludeth thus from them. _Invenio equidem, naturæ contiguam dimensionum penetrationem, licet non ordinariam. And after saith thus: Quibus constat corpora solida, satis magna, penetrasse stomachum, intestina, uterum, omentum, abdomen, pleuram, vesicam, membranas inquam, tanti vulneris impatientes. Id est, absq; vulnere cultros per istas membranas transmissos. Quod æquivalet penetrationi dimensionum, factæ in natura, absq; ope Diaboli._ And to the same purpose that most acute person, Dr. _Glisson_, handling this very point saith: _Verum enimverò, si sola quantitas actualis sit causa impenetrabilitatis corporum (ut ex supra dictis liquet,) eaq; sit naturaliter mutabilis; quid impedit ne substantia materialis aliam substantiam, mutatâ quantitate, novâq; simul assumptâ utrisq; communi, penetret?_ And therefore we may as confidently deny his assumption, that Impenetrability is the Characteristical of body, as he affirm it without proof, and must with all the whole company of the learned, assign Extension to be the true and Genuine Character of Body. And further he granting that substance hath length, breadth, and depth, we must of necessity conclude, that whatsoever hath those properties must needs be material and corporeal, and so that which he would make to be Spirit is meerly Body. [Sidenote: _Reas. 4._] [Sidenote: _Nov. organ._ _p._ 18.]