be manifest, permanent and vigorous to the utmost degree.  But on the contrary, whatsoever Body was altogether destitute of a Form, was [Greek:  Hyle], Matter without Life, and near a-kin to nothing.  And that the four Elements subsisted with one single Form only, and are of the first Rank of Beings in the sublunary World, out of which, other things endu’d with more Forms are compounded:  And that the Life of these Elements is very weak, both because they have no variety of Motion, but always tend the same way; and because every one of them has an Adversary which manifestly opposes the Tendency of its Nature, and endeavours to deprive it of its Form; and therefore its Essence is of short Continuance, and its Life weak:  But that Plants had a stronger Life, and Animals a Life more manifest than the Plants.  The reason of which is, because that whenever it happen’d, that in any of these compound Bodies, the Nature of one Element prevail’d, that predominant Element would overcome the Natures of the rest, and destroy their Power; so that the compounded Body would be of the same Nature with that prevailing Element, and consequently partake but of a small Portion of Life, because the Element it self does so.

Sec. 70.  On the contrary, if there were any of these compounded Bodies, in which the Nature of one Element did not prevail over the rest, but they were all equally mix’d, and a match one for the other; then one of them would not abate the Force of the other, any more than its own Force is abated by it, but they would work upon one another with equal Power, and the Operation of any one of them would not be more conspicuous than that of the rest; and this Body would be far from being like to any one of the Elements, but would be as if it had nothing contrary to its Form, and consequently the more dispos’d for Life; and the greater this Equality of Temperature was, and by how much the more perfect, and further distant from inclining oneway or other, by so much the farther it is distant from having any contrary to it, and its Life is the more perfect.  Now since that Animal Spirit which is seated in the Heart is of a most exact Temperature, as being finer than Earth and Water, and grosser than Fire and Air, it has the Nature of a Mean between them all, and which has no manifest Opposition to any of the Elements, and by this means is fitted to become that Form which constitutes an Animal.  And he saw that it follow’d from hence, that those Animal Spirits which were of the most even Temperature, were the best dispos’d for the most perfect Life in this World, of Generation and Corruption, and that this Spirit was very near having no opposite to its Forms, and did in this respect resemble the Heavenly Bodies which have no opposite to their Forms; and was therefore the Spirit of the Animal, because it was a Mean between all the Elements, and had no absolute Tendency, either upwards or downwards; but that, if it were possible it should be plac’d