most important respect, that whatever they may be they are not what they appear to be. A state of mind is what we feel it to be; a state of matter is certainly not what we seem to ourselves to perceive it to be. No one, of course, knew all this better than Mr Mill. He, as a philosopher, had asked himself what matter is; he had formed a theory in answer to the question. And what is his theory? Just this,--that we cannot find a permanent element in matter; that we have no right to suppose that there is a permanent real existence or actual substance in matter; that all that we are warranted to affirm about the ultimate nature of matter is that it is a permanent possibility,--the permanent possibility of sensations. That was the conclusion which he arrived at when he theorised on matter without any theological aim. But he appears to have forgotten it when he came to criticise the argument for a first cause. He could not otherwise have written as if it were quite certain that there was in matter "a permanent element," not an underlying possibility but an inherent real substance. Had he remembered what his own theory as to the nature of matter was, he would have avoided as utterly untrue and misleading every expression which could suggest the notion of there being a permanent element in matter, and would have admitted that very probably the permanent possibilities of sensation, the causes of all material phenomena, lay in the Divine will, since he had been unable to find anything else permanent in which they could be supposed to subsist. That is a view which many profound thinkers have adopted. They have been led to hold that matter is essentially force, and nothing but force; that the whole material world is ultimately resolvable into forces; and that all its forces are but manifestations or outgoings of will-force. If so, the whole material world is not only dependent on, but _is_, the will of God, and has no being of any kind apart from the will of God. If so, God's will is not only the cause and controlling power of nature, but its substance, its self. And this view, that what alone substantially underlies all the phenomena we designate material is an acting mind, an energising will, has not only been reached by mental philosophers and idealistic speculators, but by those physicists who, like Boscovitch and Faraday, have found themselves forced to conclude that what is constitutive of matter is not indivisible particles, even infinitesimally small, but mere centres of force, since force necessarily implies some sort of substance, and, therefore, spirit where not matter.