Did Murphy Go Crazy?

There's little doubt that Morphy had some "derangement" as they called it, very peculiar behavior, but he was hardly ever clinically insane. He also never divorced himself from intellectual pursuits. Leona Queyrouze is very specific that Morphy have a deep interest in music, philosophy and literature until his death.

Why did Morphy go crazy?

He lived in fear of being poisoned, eating only food prepared by his mother or sister, and he believed that neighborhood barbers were conspiring to slit his throat. His family tried to have him committed to an asylum, but he argued his sanity so convincingly that the authorities declined to admit him.

Why did Morphy stop playing chess?

Morphy retired at 14, coming out of retirement to play in 1857. He never studied and rarely played in the 6 years in between. He played for two more years, then retired again. The reason he failed as a lawyer had to do with his mental illness and the fact that he didn't serve in the Southern armies in the US Civil War.