Having thus ascertained by direct experience that there is a state of matter in which inertia is, to say the least, greatly diminished, we find ourselves in need of giving this state (which is present throughout nature wherever material changes are brought into existence magically) a name of its own, as we did with the two types of causation. A word suggests itself which, apart from expressing adequately the peculiar self-mobility which we have just brought to our experience, goes well alongside the word 'inert' by forming a kind of rhyme with it. This is the term 'alert'. With its help we shall henceforth distinguish between matter in the inert and alert conditions. We shall call the latter state 'alertness', and in order to have on the other side a word as similar as possible in outer form to alertness, we suggest replacing the usual term inertia by 'inertness'. Thus we shall speak of matter as showing the attribute of 'inertness', when it is subject to mechanical causation, of 'alertness', when it is subject to magical causation.