The usefulness of historical knowledge in philosophy, here as elsewhere, is that the prejudices of our own period may lose their grip on us if we imaginatively enter into another period, when people’s prejudices were different.
[Suicide note] - Human life consists in mutual service. No grief, pain, misfortune, or 'broken heart' is excuse for cutting off one's life while any power of service remains. But when all usefulness is over, when one is assured of an unavoidable and imminent death, it is the simplest of human rights to choose a quick and easy death in place of a slow and horrible one.
We pierce doors and windows to make a house; and it is on these spaces where there is nothing that the usefulness of the house depends. Therefore just as we take advantage of what is, we should recognize the usefulness of what is not.
Young men have strong passions, and tend to gratify them indiscriminately... They have as yet met with few disappointments. Their lives are mainly spent not in memory but in expectation; for expectation refers to the future, memory to the past, and youth has a long future before it and a short past behind it: on the first day of one’s life one has nothing at all to remember, and can only look forward... They would always rather do noble deeds than useful ones: their lives are regulated more by moral feeling than by reasoning; and whereas reasoning leads us to choose what is useful, moral goodness leads us to choose what is noble. They are fonder of their friends, intimates, and companions than older men are, because they like spending their days in the company of others, and have not yet come to value either their friends or anything else by their usefulness to themselves. All their mistakes are in the direction of doing things excessively and vehemently. They disobey Chilon’s precept by overdoing everything; they love too much and hate too much, and the same thing with everything else. They think they know everything, and are always quite sure about it.
Consider the postage stamp my son: Its usefulness consists in its ability to stick to one thing until it gets there
We are a spectacular manifestation of life. We have language... We have affection. We have genes for usefulness, and usefulness is about as close to a "common goal" of nature as I can guess at. And finally, and perhaps best of all, we have music.
A man's usefulness depends upon his living up to his ideals insofar as he can. It is hard to fail but it is worse never to have tried to succeed. All daring and courage, all iron endurance of misfortune, make for a finer, nobler type of manhood. Only those are fit to live who do not fear to die, and none are fit to die who have shrunk from the joy of the life and the duty of life.
It must be for truth's sake, and not for the sake of its usefulness to humanity, that the scientific man studies Nature. The application of science to the useful arts requires other abilities, other qualities, other tools than his; and therefore I say that the man of science who follows his studies into their practical application is false to his calling. The practical man stands ever ready to take up the work where the scientific man leaves it, and adapt it to the material wants and uses of daily life.
Does man exist for the sake of society? The ultimate worth of a person would then be determined by his usefulness to others, by the efficiency of his social work.... Such service does not claim all of one’s life and can therefore not be the ultimate answer to his quest for the meaning of life as a whole. Man has more to give than what other men are able or willing to accept. Man’s quest for a meaning of existence is essentially a quest for lasting... The way to the lasting does not lie on the other side of life; it does not begin where time breaks off. The lasting begins not beyond but within time, within the moment, within the concrete... The days of our lives are representatives of eternity rather than fugitives, and we must live as if the fate of all time would totally depend on a single moment.
Just as we take advantage of what is, we should recognize the usefulness of what is not.
Friendship is the only thing in the world concerning the usefulness of which all mankind are agreed.