One thing we can and must not fail to do:  we can learn to understand and appreciate Rest.  In particular, we should build up and reinforce the powers of the night to offset this new intensity of the day.  Such, indeed, as the day now is has it ever been, though in a less degree:  always it has cast upon men impressions significant, insignificant, and of an ill significance, promiscuously and in excess; and always sleep has been the filter of memory, the purifier of experience, providing a season that follows closely upon the impressions of the day, ere yet they are too deeply imbedded, in which our deeper life may pluck away the adhering burrs from its garments, and arise disburdened, clean, and free.  I make no doubt that Death also performs, though in an ampler and more thorough way, the same functions.  It opposes the tyranny of memory.  For were our experience to go on forever accumulating, unwinnowed, undiminished, every man would sooner or later break down beneath it; every man would be crushed by his own traditions, becoming a grave to himself, and drawing the clods over his own head.  To relieve us of these accidental accretions, to give us back to ourselves, is the use, in part, of that sleep which rounds each day, and of that other sleep—­brief, but how deep!—­which rounds each human life.

Accordingly, he who sleeps well need not die so soon,—­even as in the order of Nature he will not.  He has that other and rarer half of a good memory, namely, a good forgetting.  For none remembers so ill as he that remembers all.  “A great German scholar affirmed that he knew not what it was to forget.”  Better have been born an idiot!  An unwashed memory,—­faugh!  To us moderns and Americans, therefore, who need above all things to forget well,—­our one imperative want being a simplification of experience,—­to us, more than to all other men, is requisite, in large measure of benefit, the winnowing-fan of sleep, sleep with its choices and exclusions, if we would not need the offices of death too soon.

But a function of yet greater depth and moment remains to be indicated.  Sleep enables the soul not only to shed away that which is foreign, but to adopt and assimilate whatever is properly its own.  Dr. Edward Johnson, a man of considerable penetration, though not, perhaps, of a balanced judgment, has a dictum to the effect that the formation of blood goes on during our waking hours, but the composition of tissue during those of sleep.  I know not upon what grounds of evidence this statement is made; but one persuades himself that it must be approximately true of the body, since it is undoubtedly so of the soul.  Under the eye of the sun the fluid elements of character are supplied; but the final edification takes place beneath the stars.  Awake, we think, feel, act; sleeping, we become.  Day feeds our consciousness; night, out of those stores which action has accumulated, nourishes the vital unconsciousness, the pure unit