"Through the constant revolution of the fifth element, with all contained therein, the four elements are forced to move and to change their respective positions, so that fire and air are driven into the water, and again these three elements enter the depth of the earth. Thus are the elements mixed together; and when they return to their respective places, parts of the earth, in quitting their places, move together with the water, the air and the fire. In this whole process the elements act and react upon each other. The elements intermixed, are then combined, and form at first various kinds of vapours; afterwards the several kinds of minerals, every species of plants, and many species of living beings, according to the relative proportion of the constituent parts. All transient beings have their origin in the elements, into which again they resolve when their existence comes to an end. The elements themselves are subject to being transformed from one into another; for although one substance is common to all, substance without form is in reality impossible, just as the physical form of these transient beings cannot exist without substance."