This peculiarity must be due to the fact that the man’s character has something in it akin to the qualities of youth or manhood or old age—­something which accords with one or another of these periods of life, or perhaps acts as a corrective to its special failings.

The mariner observes the progress he makes only by the way in which objects on the coast fade away into the distance and apparently decrease in size.  In the same way a man becomes conscious that he is advancing in years when he finds that people older than himself begin to seem young to him.

It has already been remarked that the older a man becomes, the fewer are the traces left in his mind by all that he sees, does or experiences, and the cause of this has been explained.  There is thus a sense in which it may be said that it is only in youth that a man lives with a full degree of consciousness, and that he is only half alive when he is old.  As the years advance, his consciousness of what goes on about him dwindles, and the things of life hurry by without making any impression upon him, just as none is made by a work of art seen for the thousandth time.  A man does what his hand finds to do, and afterwards he does not know whether he has done it or not.

As life becomes more and more unconscious, the nearer it approaches the point at which all consciousness ceases, the course of time itself seems to increase in rapidity.  In childhood all the things and circumstances of life are novel; and that is sufficient to awake us to the full consciousness of existence:  hence, at that age, the day seems of such immense length.  The same thing happens when we are traveling:  one month seems longer then than four spent at home.  Still, though time seems to last longer when we are young or on a journey, the sense of novelty does not prevent it from now and then in reality hanging heavily upon our hands under both these circumstances, at any rate more than is the case when we are old or staying at home.  But the intellect gradually becomes so rubbed down and blunted by long habituation to such impressions that things have a constant tendency to produce less and less impression upon us as they pass by; and this makes time seem increasingly less important, and therefore shorter in duration:  the hours of the boy are longer than the days of the old man.  Accordingly, time goes faster and faster the longer we live, like a ball rolling down a hill.  Or, to take another example:  as in a revolving disc, the further a point lies from the centre, the more rapid is its rate of progression, so it is in the wheel of life; the further you stand from the beginning, the faster time moves for you.  Hence it may be said that as far as concerns the immediate sensation that time makes upon our minds, the length of any given year is in direct proportion to the number of times it will divide our whole life:  for instance, at the age of fifty the year appears to us only one-tenth as long as it did at the age of five.