Pasteur could not become resigned to the humiliation of France, and, tearing his thoughts from the nightmare of the war and the Commune, he dwelt continually on the efforts that would be necessary to carry out the great task of raising the country once again to its proper rank. In his mind it was the duty of every one to say, “In what way can I be useful?” Each man should strive not so much to play a great part as to give the best of his ability. He had no patience with those who doubt everything in order to have an excuse for doing nothing. He had indeed known dark moments of doubt and misgivings, as even the greatest minds must do, but notwithstanding these periods of discouragement he was convinced that science and peace will ultimately triumph over ignorance and war. In spite of recent events, the bitter conditions of peace which tore unwilling Alsace and part of Lorraine away from France, the heavy tax of gold and of blood weighing down future generations, the sad visions of young men in their prime cut down on the battlefield or breathing their last in hospitals all to no apparent purpose; in spite of all these sad memories he was persuaded that thinkers would gradually awaken in the nations ideas of justice and of concord. He had now for nine years been following with a passionate interest some work begun in his own laboratory by Raulin, his first curator. Some of the letters he wrote to Raulin during those nine years give us a faint idea of the master that Pasteur was. It had been with great regret that Raulin had left the laboratory in obedience to the then laws of the University in order to take up active work at the Brest college, and Pasteur’s letters (December, 1862) brought him joy and encouragement: “Keep up your courage, do not allow the idleness of provincial life to disturb you. Teach your pupils to the very best of your ability and give up your leisure to experiments; this was M. Biot’s advice to myself.” When in July, 1863, he began to fear that Raulin might allow imagination to lead him astray in his work, he repeatedly advised him to state nothing that could not be proved: “Be very strict in your deductions”; then, apparently, loth to damp the young man’s ardour: “I have the greatest confidence in your judgment; do not take too much heed of my observations.”