From what I have said in the last chapter, it is plain that, perhaps before very long, it will be possible to modify old age. Instead of retaining its existing melancholy and repulsive character, it may become a healthy and endurable process; it may also be that the duration of life will be prolonged. However, it may be asked, what shall we gain by attaining the age of 100 or 120 years instead of 70 or 80, if there still remain for us the appalling fate of the inevitable annihilation of death. Marcus Aurelius said that he who makes a long journey and he who makes it short, alike meet death at the end; and that once they are over, three years or a century are much alike. Such assertions, however, do not take into account the difference in the values we set on a thing at different ages. A man of the age of twenty-five years and one fifty years old reason differently, and are affected differently by the same surroundings. The outlook on life changes in the same individual as he gets on in years. Young people judge of their impressions by comparison with their ideals, and as the latter are very high, they are dissatisfied with things as they really are. They are exacting, and discontented with what they can get out of the real world; grown up people and those of advanced years are more easily satisfied because they have a clearer knowledge of the true value of things. As I have already had occasion to point out in a previous chapter, the young are more inclined to pessimism than the old. We see, then, that appreciation of life changes with age. It is the same with regard to death. It has often been said that life is only a preparation for death. Cicero said, “From our youth upwards we must accustom ourselves to face our last moments without fear. If not, there is an end to peace, since it is quite certain that we must die.” Philosophy has been called the art of preparing for death. Before considering in what direction science may direct our steps towards solving the problem of death, which in the words of St. Paul is the “last enemy to be destroyed,” let us see how much is known about it.