In either case,—the repose of perfect ignorance or of perfect knowledge—disturbance is troublesome. When first starting on an Atlantic steamer, our rest is hindered by the screw; after a short time, it is hindered if the screw stops. A uniform impression is practically no impression. One cannot either learn or unlearn without pains or pain. CHAPTER II. CONSCIOUS AND UNCONSCIOUS KNOWERS—THE LAW AND GRACE. IN this chapter we shall show that the law, which we have observed to hold as to the vanishing tendency of knowledge upon becoming perfect, holds good not only concerning acquired actions or habits of body, but concerning opinions, modes of thought, and mental habits generally, which are no more recognised as soon as firmly fixed, than are the steps with which we go about our daily avocations. I am aware that I may appear in the latter part of the chapter to have wandered somewhat beyond the limits of my subject, but, on the whole, decide upon leaving what I have written, inasmuch as it serves to show how far-reaching is the principle on which I am insisting. Having said so much, I shall during the remainder of the book keep more closely to the point. Certain it is that we know best what we are least conscious of knowing, or at any rate least able to prove, as, for example, our own existence, or that there is a country England. If any one asks us for proof on matters of this sort, we have none ready, and are justly annoyed at being called to consider what we regard as settled questions. Again, there is hardly anything which so much affects our actions as the centre of the earth (unless, perhaps, it be that still hotter and more unprofitable spot the centre of the universe), for we are incessantly trying to get as near it as circumstances will allow, or to avoid getting nearer than is for the time being convenient. Walking, running, standing, sitting, lying, waking, or sleeping, from birth till death it is a paramount object with us; even after death—if it be not fanciful to say so—it is one of the few things of which what is left of us can still feel the influence; yet what can engross less of our attention than this dark and distant spot so many thousands of miles away? The air we breathe, so long as it is neither too hot nor cold, nor rough, nor full of smoke—that is to say, so long as it is in that state within which we are best acquainted—seldom enters into our thoughts; yet there is hardly anything with which we are more incessantly occupied night and day.