In spite of the consensus of adverse, and somewhat vicious opinion, the author of the _Tractatus_ did find favor in the eyes of some. The Elector Palatine, Karl Ludwig, through his secretary Fabritius, offered Spinoza the chair of philosophy at Heidelberg (1673). But Spinoza graciously declined it. Although a more welcome or more honorable opportunity to teach could not be conceived, it had never been his ambition to leave his secluded station in life for one involving public obligations. Even in his secluded corner, he found he had aroused more public attention and sentiment than was altogether consonant with the peace and retirement he sought. Besides, he did not know how well he could fulfill the desires of the Elector by teaching nothing that would tend to discomfit established religion. Spinoza had, in his young days, learned what extreme dangers one must expect to encounter in a righteous community become inimical. In his last years, he experienced a stern and tragic reminder. Two of Spinoza's best friends, Cornelius and Jan de Witt, who had by a change in political fortune become the enemies of the people, were brutally murdered (1672). Spinoza for once, when this occurred, lost his habitual philosophic calm. He could restrain neither his tears nor his anger. He had to be forcibly prevented from leaving his house to post a bill, at the scene of the murder, denouncing the criminal mob. A somewhat similar crisis recurred shortly afterwards when Spinoza returned from a visit to the hostile French camp. The object of his mission is not unequivocally known. Some think it was to meet the Prince of Condé solely in his private capacity of philosopher. It is certain Spinoza was advised the French King would acknowledge a dedicated book by means of a pension--an advice Spinoza did not act upon. Others think his mission was political. His reputation as a distinguished man would have made him a very likely ambassador. This conjecture would seem more probable, however, if the de Witts, his intimate friends, had been still in political power, instead of in their graves. But whatever Spinoza's mission was, when he returned to the Hague, the populace branded him a French spy. Spinoza's landlord feared his house would be wrecked, by an infuriated mob. This time Spinoza exerted the calming influence. He assured Van der Spijck that if any attempt were made on the house he would leave it and face the mob, even if they should deal with him as they did with the unfortunate de Witts. He was a good republican as all knew. And those in high political authority knew the purpose of his journey. Fortunately, popular suspicion and anger dissipated this time without a sacrifice. Still, the incident showed quite clearly that though Spinoza did not desire to be a martyr, he was no more afraid to die than he was to live for the principles he had at heart.