After this he proceeded further to examine the nature of bodies that were subject to generation and corruption, as the different kinds of animals, plants, minerals and different sorts of stones, earth, water, exhalations and vapours, ice, snow, hail, smoke, fire, and hoar-frost.

In all these he observed different qualities and a diversity of actions and motions, agreeing in some respects and differing in others. He found that, so far as they agreed, they were one; where they disagreed, a great many; and when he looked into the properties whereby they were distinguished from one another, he found them so manifold that he could not comprehend them.

As to himself, he knew that his spirit was one in essence, and was really the substance of his being, and that the other parts served only as so many instruments. So he perceived his own essence to be but one.

Then attentively considering the different kinds of animals, he perceived that the one thing common to them all was sensation and nutrition and the faculty of moving of their own accord wheresoever they pleased, all of which actions he was assured were the proper effects of the animal spirit, and that those lesser things in which they differed were not so proper to that spirit.

For he considered that the animal spirit may differ with regard to some qualities, according to the variety of constitutions in several animals. And so he looked upon the whole species of living creatures as one.

Then, on contemplating the different species of plants, he perceived that the individuals of every species were like one another in their boughs, branches, leaves, fruits; and so, taking a view of all the different kinds of plants, he decided within himself that they were all one and the same in respect of that agreement between themselves in their actions, viz. their nourishment and growth.

He then contemplated those bodies which have neither sense, nourishment, nor growth, such as stones, earth, water, air, and fire; which he saw had all of them three dimensions, viz. length, breadth, and thickness; and that their differences only consisted in this, that some of them were coloured, others not; some were hot, others cold, and similar differences.

He noticed also that hot bodies grew cold, and, on the contrary, cold ones grew warm. He saw further that water rarefied into vapours, and vapours again thickened and turned into water. Then he observed that the bodies which were burnt turned into coals, ashes, flame, and smoke; and that the smoke, when in its ascent it was intercepted by an arch of stones, thickened them into soot, and became like other earthly substances. From whence he concluded that all things were in reality one, like the animals and plants, though multiplied and diversified in some respects.