8. It is a general principle that, to be modified, an object must be opposed in faculty, and in quality to the forces that enter and act upon it.
Thus where heat is present, the change comes by something that chills, where damp by some drying agency: we say a subject is modified when from warm it becomes cold, from dry wet.
A further evidence is in our speaking of a fire being burned out, when it has passed over into another element; we do not say that the Matter has been burned out: in other words, modification affects what is subject to dissolution; the acceptance of modification is the path towards dissolution; susceptibility to modification and susceptibility to dissolution go necessarily together. But Matter can never be dissolved. What into? By what process?
Still: Matter harbours heat, cold, qualities beyond all count; by these it is differentiated; it holds them as if they were of its very substance and they blend within it – since no quality is found isolated to itself – Matter lies there as the meeting ground of all these qualities with their changes as they act and react in the blend: how, then, can it fail to be modified in keeping? The only escape would be to declare Matter utterly and for ever apart from the qualities it exhibits; but the very notion of Substance implies that any and every thing present in it has some action upon it.