Young men, have confidence in those powerful and safe methods, of which we do not yet know all the secrets. And, whatever your career may be, do not let yourselves become tainted by a deprecating and barren scepticism, do not let yourselves be discouraged by the sadness of certain hours which pass over nations. Live in the serene peace of laboratories and libraries. Say to yourselves first : "What have I done for my instruction?" and , as you gradually advance, "What have I done for my country?" until the time comes when you may have the immense happiness of thinking that you have contributed in some way to the progress and to the good of humanity. But, whether our efforts are or not favoured by life, let us be able to say, when we come near the great goal, "I have done what I could."
• Variant translation:

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "Young men, have confidence in those powerful and safe methods, of which we do not yet know all the secrets. And, whatever your career may be, do not let yourselves become tainted by a deprecating and barren scepticism, do not let yourselves be discouraged by the sadness of certain hours which pass over nations. Live in the serene peace of laboratories and libraries. Say to yourselves first : "What have I done for my instruction?" and , as you gradually advance, "What have I done for my country?" until the time comes when you may have the immense happiness of thinking that you have contributed in some way to the progress and to the good of humanity. But, whether our efforts are or not favoured by life, let us be able to say, when we come near the great goal, "I have done what I could."
• Variant translation:" in the context of "The Life of Pasteur (1911), Volume II, p. 228
 • Do not let yourself be tainted with a barren skepticism.
• As quoted in The Louisville & Nashville Employes' Magazine Vol. 21 (1944)‎, p. 28" to mean that wisdom is timeless.