A Prince of the Captivity by John Buchan

As Adam dressed for dinner in his little Temple bedroom, which looked out on the top of a dusty plane tree and a flat-chested building of old brick, he had one of his rare moments of introspection when he tried to orientate himself with the world.

He was living a normal life again in close contact with his fellows. To that he had schooled himself -- not without difficulty after his six years of solitude. He had a task before him which absorbed all his energies of mind and body, but he had early realised that he must fail if he regarded people as only figures in a mathematical problem. So he laboured to cultivate the common sympathies. But he knew that his success was limited. He understood them and could use them, but they did not deeply move him. Marrish was a case in point. He had saved the man from disaster, and Marrish's letters now were full of a doglike worshipping affection. But for Marrish himself he had no strong feeling; he had been only an incident in Utlaw's life. Utlaw was the vital matter. Yet how much did he care for Utlaw apart from Utlaw's political career? . Adam laid down his brushes and regarded his face in the mirror. All his emotions were now tenuous things with a utilitarian purpose. Might not this lack of an ultimate human warmth be fatal in some critical hour?