In a letter to the Wall Street Journal, Alfred Ironside, vice president for global communications, responded to a recent piece in the paper critical of the foundation. Former hedge fund manager Andy Kessler had taken issue with our plan to dedicate resources to fighting inequality: “Society benefits from making, not giving,” he wrote.

“We share Andy Kessler’s view that Henry Ford and other visionary makers in every era are huge contributors to economic prosperity,” Ironside allowed. But:

Ford helped transform America in part because he recognized his workers ought to be able to buy the cars they were building. But inequality isn’t just economic, and markets aren’t society’s sole levelers.

By providing risk capital to social innovators, philanthropy creates value that markets don’t. Early Ford Foundation investments in microfinance and the green revolution, for instance, helped bring hundreds of millions of people into markets. Support for the anti-apartheid movement and human rights leaders in Latin America and the Soviet bloc contributed to the rise of global democracy. Investments in ideas like Head Start and Pell grants put opportunity in reach for millions of poor Americans. And support for civil rights has enabled people to fight for their right to participate fully in the economic and political life of the country.

Catalytic gains like these, nurtured by the philanthropic giving Mr. Kessler derides (and often brought to scale by smart government investment), cannot be measured on an earnings statement, to be sure. Yet the multiples of value they have created for society as a whole are undeniable.

Unlike Mr. Kessler, we find no difficulty in reconciling our belief in individual enterprise and ingenuity with an equally profound belief in the lasting gains in American well-being that come when all sectors—private, public and nonprofit—work together.

Read the letter alongside other responses to Kessler’s piece.