Conservatives, beware: You can have reams of information, piles of studies and folders of charts at your fingertips. And you can still lose the debate.

That’s because you’ve overlooked a crucial component: the moral case. And that, according to Arthur C. Brooks, can often make or break your argument.

Brooks, who started his career as a member of the Barcelona Symphony in Spain, is president of the American Enterprise Institute in Washington, D.C. In his latest book, “The Road To Freedom: How To Win The Fight For Free Enterprise,” Brooks offers a powerful defense of American values, and explains how we can save our country from financial ruin by returning to our free-market roots.

The numbers are daunting. “The Congressional Budget Office tells us that by 2038, government spending will be 50 percent of GDP,” he writes. “Americans will work from January 1 until June 30 each year just to pay for the government – a government that a large majority of us believes has too much power, tries to do too much, and provides unsatisfactory services.”

But again, numbers aren’t enough. We need the moral case.

“Anyone who reads the words of the Founders,” Brooks writes, “cannot miss their keen emphasis on the morality of the systems they intended to create. Our ideas about free enterprise and liberty were born from a sense of what is right and what helps us to thrive as people, not from a monomaniacal obsession with what makes us rich.”

Historian Matthew Spalding echoes this theme in his book We Still Hold These Truths : “As the Founders saw it, the right to property was not simply an economic concept, and was much more than owning a bit of land. It was a first principle of liberty. The essence of liberty is the freedom to develop one’s talents, pursue opportunity, and generally take responsibility for one’s own life and well-being.”

Brooks calls that “earned success,” and he’s got plenty of social science research that shows people are happier when they have a chance to earn their success. That doesn’t mean equality of outcome, however. Some people are always going to do better than others, and Americans understand and accept that.

It does mean equality of opportunity. Government should protect property rights, encourage entrepreneurs and enforce reasonable regulations. Otherwise, it should stay out of the way and allow people the freedom to thrive, whether that means earning a lot of money, or volunteering for a charitable cause.

“Around the world, it is the moral case, not an economic one, that leads people to take risks for freedom,” Brooks writes. “Advances in the cause of freedom and free enterprise – while less dramatic than the collapse of communism – have succeeded when advocates have made a compelling moral case for it.”

Brooks also warns against the opposite of “earned success,” which he calls “learned hopelessness.” This is what happens when people cease to believe that they’re capable of controlling their own destiny or improving their lives. Consider welfare before the 1996 reform package.

“Welfare programs created a permanent underclass: the unemployed received unearned support, lost job skills (or never acquired them), and thus became unable to gain stable employment, making them chronically, miserably, reliant on state aid,” Brooks writes. Too many people had “learned” that there was nothing they could do to improve their lives.

It took decades to make the moral case for welfare reform. But millions of Americans are better off today than they were when they relied on the federal government.

Since 1970 alone, free-market economic policies have lifted hundreds of millions of people out of poverty. They have saved and improved countless people’s lives.

That’s worth keeping in mind as we debate policy in the public square. Yes, we need numbers. But Brooks is right: If we want to build a better society, we need to seize the moral high ground as well.