NEW YORK (FORTUNE) -- Business is business.

That's an expression we've heard countless times. As I've watched FORTUNE 500 companies change dramatically - as a group, they are becoming more green, more diverse, more transparent and more willing to define their responsibilities broadly - I've always assumed that these companies are evolving purely for business reasons.

I've written that companies become more socially responsible to protect their brands, to engage their people or to appeal to a certain set of customers who care about reputation.

But business is personal, too.

Business got personal at FORTUNE's recent Brainstorm conference when top executives talked about their latest, best ideas. Entrepreneur Bill Gross described Energy Innovations, his solar power business. Venture capitalist Vinod Khosla touted his investments in biofuels. Sun Microsystems' John Gage described his company's role in bringing mobile phone service to the African nation of Rwanda.

More than the bottom line is driving all these efforts. They are all personal. Each of these men care passionately about the causes their companies are engaged in.

So, too, are the businesses in a new book called "True to Yourself: Leading a Values-Based Business." The book's author, Mark Albion, is a writer, entrepreneur, a consultant to Fortune 500 companies and a former Harvard Business School professor. (Disclosure: I've known Albion for years, and he sent me an early draft of the book to review.)

In "True to Yourself," Albion argues that the personal side of business must come first. Only then will profits follow.

"Values-based leaders focus on their impact on people and the planet," he says. "And when they do it well - building a company or division that reflects their values - it results in more meaningful lives and financial health."

The argument here - an increasingly familiar one - is that leaders and companies can do well by doing good. "True to Yourself" was written with the Social Venture Network, an organization of businesses, investors and NGOs that promotes the idea that business should support a more just and sustainable economy.

In the book, Albion cites dozens of examples of values-based businesses - mostly smaller firms like Seventh Generation, which produces environmentally-safe household products, Bright Horizons, which provides on-site day care, and Honest Tea, which makes organic bottled drinks. They began with a founder's desire to make a difference. Business success came later.

An expert on leadership, Albion offers practical advice to executives who want to lead values-based businesses. He argues that a new style of open, collaborative leadership is required, and that strong, long-term relationships are the glue that holds companies together. Today's leaders need to be listeners, learners and teachers, he says. There's lot's more along these lines at his Web site, www.makingalife.com.

Particularly in a startup, Albion writes, the leader's values are crucial. "The day you launch your company, you are its first product," he notes. "You must sell your values, your mission, your uniqueness to others."

Big public companies are different, of course. They have to answer to a broad array of shareholders. They can't embark on a venture that's good for the world unless they are reasonably sure that it will also be good for their business.

But big companies are personal in the sense that they depend on persuading people to commit themselves to big goals. "The way you really make change is by capturing the hearts and minds of your people," says Albion, paraphrasing Jack Welch, the former CEO of General Electric.

Occasionally, even the CEOs of global giants get personal. Recently, I talked to Wal-Mart (Charts) CEO Lee Scott about sustainability. He cited a slew of very solid business reasons to explain why Wal-Mart wants to lead the way in solving environmental problems.

Then, he added: "I worry because I do have a 3-year-old granddaughter. What will this world be like for her?"

That will be Scott's legacy. That's personal. Mark Albion argues persuasively that there's no need to draw a line between what's personal and what's business, or to separate who you are from what you do.

"If you leave what is most special about you at home, how can you make a unique contribution to the world?" he asks. "And who wants to live that way, anyway?"

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