Neither, if, withdrawing our eyes from the outward world, we cast them inwardly upon the operations of our own minds, shall we, according to Hume, any the more discover what we are in search of. What though we know by experience that whatever, within certain limits, our will appoints, our bodily organs or mental faculties will ordinarily perform; that our limbs will move as we wish them, and our memory, reason, or imagination bring forward ideas which we desire to contemplate, what knowledge have we here beyond that of certain volitions and certain other acts taking place in succession? What smallest evidence have we of any connection between the volitions and the other acts? A volition is an operation of the mind, is it not? and body is matter, is it not? And do you pretend to know--can you form the smallest approach to a guess--how mind is united with body, and how it is possible therefore for the refined spiritual essence to actuate the gross material substance. If you 'were empowered by a secret wish to remove mountains or to control the planets in their orbit,' would such extensive authority be one whit more inexplicable than the supposed ability of your will to raise your hand to your head or to cause your foot to make one forward step? If, nevertheless, you fancy you understand in what manner the will has some of the bodily organs under its government, how, pray, do you account for its not having all equally--the heart and liver as well as the tongue and fingers? Without trying, you never would have discovered that your bowels _will not_, any more than without trying you could have known that your limbs _will_, ordinarily move in conformity with your wishes. Neither, if one of your limbs were to be suddenly paralysed, would you, until you tried, become aware that it would no longer move as you wished. If there be, then, a power attached to the will, it is plainly experience alone which apprises you of its existence; whereas if you were independently conscious of it, you would know beforehand precisely what it can and what it cannot effect, and would, moreover, when you lost it, become instantly aware of your loss. Again, and above all, does not anatomy teach us that when the mind wills the movement of any bodily member, it 'is not the member itself which is immediately moved, but certain intervening nerves, muscles, and animal spirits, or possibly something still more minute and more unknown,' through which the motion is successively propagated until it reach the member? So that when the mind wills one event, a series of other events, quite different and quite unthought of, take place instead; and it is only by their means that the will's purpose is finally achieved. But how can the mind be conscious, how can it form the remotest conception, of a power which not only never does what the mind desires, but never does aught of which the mind is cognisant?