Mr. Carney sounded like a friend of banks compared with another speaker at the same conference.

Christine Lagarde, the managing director of the International Monetary Fund, spoke of “scandals that violate the most basic ethical principles,” including illegal foreclosures, money laundering and the fixing of interest rate benchmarks. “While some changes in behavior are taking place, these are not deep or broad enough,” she said. “The industry still prizes short-term profit over long-term prudence, today’s bonus over tomorrow’s relationship.”

At the heart of the new regulatory spirit is a belief that banks are not, in and of themselves, necessarily good things. “In the run-up to the crisis,” Mr. Carney said, “banking became about banks not businesses; transactions not relations; counterparties not clients. New instruments originally designed to meet the credit and hedging needs of businesses quickly morphed into ways to amplify bets on financial outcomes.”

Ms. Lagarde added that “the true role of the financial sector is to serve, not to rule, the economy. Its real job is to benefit people, especially by financing investment and thus helping with the creation of jobs and growth.”

That kind of talk can sound scary in bank boardrooms, where regulators are expected to set rules and then let banks do what they wish to do so long as they remain within the letter of the law.

United States bank regulators have spoken several times in recent months of taking “reputational risk” into account in monitoring banks. In one case, the Federal Deposit Insurance Corporation and the Office of the Comptroller of the Currency warned that “engaging in practices that are perceived to be unfair or detrimental to the customer can cause a bank to lose community support and business.”

To Representative Jeb Hensarling, the Texas Republican who leads the House Financial Services Committee, that sounds suspicious. “It would be an abuse of regulatory discretion to use vague, subjective and unquantifiable indicators to justify regulatory outcomes that could not otherwise be justified,” he wrote in a letter to bank regulators last week. He asked that they explain by June 12 how they could legally use such discretion.