"An unwarranted outbreak of temper"
Peirce’s relationship with Carus was not always amicable. There were moments when Peirce was personally affronted by Carus’s philosophical retorts. The first instance of this occurs in late May when Peirce apparently sent an angry letter to Carus concerning Carus’s published note objecting to Peirce’s article on tychism. Carus in his response on 23 May attempts to pacify Peirce by reassuring him that he remains open to receiving and publishing Peirce’s contrary positions. "You might have known that I am willing to do whatever I can for you, and that I wish to bring your ideas before the public as affectually as possible…. Being disposed toward you as I am, I was surprised to receive a letter from you which I do not know whether I shall take it as an insult or an unwarranted outbreak of temper." Carus continues by explaining that he is, nonetheless, obligated to Hegeler to defend philosophical monism: “It is my duty to say something by way of reply to your first article, not so much in criticism of your position, as in order to state the position of the MONIST.”
Peirce is contrite in his reply to Carus:
“I must plead guilty to the charge of using an offensive expression in regard to your possible reply. I much regret it, and ask your pardon. It was a case of the pen of a tired and hurried man running away and making him say things whose portée he did not perceive. One of ‘things one would rather have left unsaid.’”
Over the years Peirce also experienced misunderstandings and confrontations with the Open Court’s owner, Hegeler. These, however, would not be so short-lived, and Peirce held a secret animosity toward Hegeler as a businessman throughout their professional relationship.