Somebody someday may publish a penetrating study of Elon Musk, the astonishingly rich genius who has a record of amazing accomplishments, but appears to be suffering from atrophy of the region of his brain responsible for exercising judgment. Recently, he’s been clutching nuggets of disinformation as if they were pure gold, even asserting that Dr. Anthony Fauci, the nation’s leading expert on infectious diseases, who has a long record of honorable service to the country, should be criminally prosecuted. In her book Self-Constitution: Agency, Identity, and Integrity, Harvard philosopher Christine Korsgaard notes that people who have lack moral integrity “are nothing but a heap of impulses.” Irrational impulses seem to be propelling Mr. Musk, rather than the celebrated reasoning powers of his brain.