On his return to his study in the Rue d’Ulm, Pasteur again took up the management of the scientific studies of the Ecole Normale. But an incident put an end to his directorship, while bringing perturbation into the whole of the school. Sainte Beuve was the indirect cause of this small revolution. The Senate, of which he was a member, had had to examine a protest from 102 inhabitants of St. Etienne against the introduction into their popular libraries of the works of Voltaire, J. J. Rousseau, Balzac, E. Renan, and others. The committee had approved this petition in terms which identified the report with the petition itself. Sainte Beuve, too exclusively literary in his tastes, and too radical in his opinions to be popular in the Senate, rose violently against this absolute and arbitrary judgment, forgetting everything but the jeopardy of free opinions before the excessive and inquisitorial zeal of the Senate. His speech was very unfavourably received, and one of his colleagues, M. Lacaze, aged sixty-eight, challenged him to a duel. Sainte Beuve, himself then sixty-three years old, refused to enter into what he called “the summary jurisprudence which consists in strangling a question and suppressing a man within forty-eight hours.” The students of the Ecole Normale deputed one of their number to congratulate Sainte Beuve on his speech, and wrote the following letter-- “We have already thanked you for defending freedom of thought when misjudged and attacked; now that you have again pleaded for it, we beg you to receive our renewed thanks. “We should be happy if the expression of our grateful sympathy could console you for this injustice. Courage is indeed required to speak in the Senate in favour of the independence and the rights of thought; but the task is all the more glorious for being more difficult. Addresses are now being sent from everywhere; you will forgive the students of the Ecole Normale for having followed the general lead and having sent their address to M. Sainte Beuve.” This letter was published in a newspaper. Etienne Arago published it without remembering the Université by-laws which forbade every sort of political manifestation to the students. It had given pleasure to Sainte Beuve, the pleasure that elderly men take in the applause of youth; but he soon became uneasy at the results of this noisy publicity.