Mind-Body.

Bob had not noticed the skeleton before, and its sudden inclusion in the conversation made him uneasy. “I beg your pardon, sir, ‘twas disgraceful—” “Oh, stop!” Eliza hissed, “he is a Philosopher, he cares not.” “Descartes used to come up here when I was a young man, and sit at that very table, and drink too much and discourse of the Mind-Body Problem,” Huygens mused. “Problem? What’s the problem? I don’t see any problem,” Bob muttered parenthetically, until Eliza crowded back against him and planted a heel on his instep. “So Eliza’s attempt to clarify your mental processes by purging you of imbalancing humours could not have been carried out in a more appropriate location,” Huygens continued.

Neal Stephenson: Quicksilver