“Cogito, ergo sum,” murmured Vance. “Y’ know, the naturalistic philosophy of Descartes has always rather appealed to me. It was a departure from universal doubt and a seeking for positive knowledge in self-consciousness. Spinoza in his pantheism, and Berkeley in his idealism, quite misunderstood the significance of their precursor’s favorite enthymeme. Even Descartes’ errors were brilliant. His method of reasoning, for all its scientific inaccuracies, gave new signif’cation to the symbols of the analyst. The mind, after all, if it is to function effectively, must combine the mathematical precision of a natural science with such pure speculations as astronomy. For instance, Descartes’ doctrine of Vortices⸺”
“Oh, be quiet,” growled Markham. “I’m not insisting that you reveal your precious information. So why burden me with a dissertation on seventeenth-century philosophy?”
“Anyhow, you’ll admit, won’t you,” asked Vance lightly, “that, in elim’nating those disturbing cigarette butts, so to speak, I’ve elim’nated Miss St. Clair as a suspect?”
Markham did not answer at once. There was no doubt that the developments of the past hour had made a decided impression upon him. He did not underestimate Vance, despite his persistent opposition; and he knew that, for all his flippancy, Vance was fundamentally serious. Furthermore, Markham had a finely developed sense of justice. He was not narrow, even though obstinate at times; and I have never known him to close his mind to the possibilities of truth, however opposed to his own interests. It did not, therefore, surprise me in the least when, at last, he looked up with a gracious smile of surrender.
“You’ve made your point,” he said; “and I accept it with proper humility. I’m most grateful to you.”
Vance walked indifferently to the window and looked out.
“I am happy to learn that you are capable of accepting such evidence as the human mind could not possibly deny.”
I had always noticed, in the relationship of these two men, that whenever either made a remark that bordered on generosity, the other answered in a manner which ended all outward show of sentiment. It was as if they wished to keep this more intimate side of their mutual regard hidden from the world.
Markham therefore ignored Vance’s thrust.
“Have you perhaps any enlightening suggestions, other than negative ones, to offer as to Benson’s murderer?” he asked.