The day has been considered as an image of the year, and the year as the representation of life. The morning answers to the spring, and the spring to childhood and youth; the noon corresponds to the summer, and the summer to the strength of manhood. The evening is an emblem of autumn, and autumn of declining life. The night with its silence and darkness shows the winter, in which all the powers of vegetation are benumbed; and the winter points out the time when life shall cease, with its hopes and pleasures.
He that is carried forward, however swiftly, by a motion equable and easy, perceives not the change of place but by the variation of objects. If the wheel of life, which rolls thus silently along, passed on through undistinguishable uniformity, we should never mark its approaches to the end of the course. If one hour were like another; if the passage of the sun did not show that the day is wasting; if the change of seasons did not impress upon us the flight of the year; quantities of duration equal to days and years would glide unobserved. If the parts of time were not variously coloured, we should never discern their departure or succession, but should live thoughtless of the past, and careless of the future, without will, and perhaps without power, to compute the periods of life, or to compare the time which is already lost with that which may probably remain.
But the course of time is so visibly marked, that it is observed even by the birds of passage, and by nations who have raised their minds very little above animal instinct: there are human beings whose language does not supply them with words by which they can number five, but I have read of none, that have not names for day and night, for summer and winter.
Yet it is certain, that these admonitions of nature, however forcible, however importunate, are too often vain; and that many who mark with such accuracy the course of time, appear to have little sensibility of the decline of life. Every man has something to do which he neglects; every man has faults to conquer which he delays to combat.
So little do we accustom ourselves to consider the effects of time, that things necessary and certain often surprise us like unexpected contingencies. We leave the beauty in her bloom, and, after an absence of twenty years, wonder, at our return, to find her faded. We meet those whom we left children, and can scarcely persuade ourselves to treat them as men. The traveller visits in age those countries through which he rambled in his youth, and hopes for merriment at the old place. The man of business, wearied with unsatisfactory prosperity, retires to the town of his nativity, and expects to play away the last years with the companions of his childhood, and recover youth in the fields, where he once was young.