In 1989, Peter L. Bernstein was 70 and had led a full life. An intelligence officer during World War II, he later taught economics, ran an investment firm and edited the wonky but influential Journal of Portfolio Management as a flood of new academic research transformed investing in the 1970s and '80s.
But when a book editor suggested Bernstein write a memoir, he countered with an ambitious proposal for an intellectual history. The result was Capital Ideas: The Improbable Origins of Modern Wall Street, an improbably charming tale of index funds, mathematical options-pricing models and new theories of corporate finance. It...