But this way of removing the picture of human life to a certain distance from us, and considering those things which were once in a high degree interesting as frivolous and unworthy of regard, is not the way by which we shall arrive at a true and just estimation of life. Whatever is now past, and is of little value, was once present: and he who would form a sound judgment, must look upon every part of our lives as present in its turn, and not suffer his opinion to be warped by the consideration of the nearness or remoteness of the object he contemplates. One sentence, which has grown into a maxim for ever repeated, is remarkable for the grossest fallacy: Ars longa, vita brevis(9). I would fain know, what art, compared with the natural duration of human life from puberty to old age, is long. (9) Art is long; life is short. If it is intended to say, that no one man can be expected to master all possible arts, or all arts that have at one time or another been the subject of human industry, this indeed is true. But the cause of this does not lie in the limited duration of human life, but in the nature of the faculties of the mind. Human understanding and human industry cannot embrace every thing. When we take hold of one thing, we must let go another. Science and art, if we would pursue them to the furthest extent of which we are capable, must be pursued without interruption. It would therefore be more to the purpose to say, Man cannot be for ever young. In the stream of human existence, different things have their appropriate period. The knowledge of languages can perhaps be most effectually acquired in the season of nonage. At riper years one man devotes himself to one science or art, and another man to another. This man is a mathematician; a second studies music; a third painting. This man is a logician; and that man an orator. The same person cannot be expected to excel in the abstruseness of metaphysical science, and in the ravishing effusions of poetical genius. When a man, who has arrived at great excellence in one department of art or science, would engage himself in another, he will be apt to find the freshness of his mind gone, and his faculties no longer distinguished by the same degree of tenacity and vigour that they formerly displayed. It is with the organs of the brain, as it is with the organs of speech, in the latter of which we find the tender fibres of the child easily accommodating themselves to the minuter inflections and variations of sound, which the more rigid muscles of the adult will for the most part attempt in vain.