Should your business strive to be a force for good? Or is the only point of being in business to make a profit?

Tough question. Without giving away too much of this month's cover story, I can tell you that Shark Tank's professional curmudgeon, Kevin O'Leary, favors the "make a profit" side. Adam Lowry, the co-founder of eco-conscious Method Products, believes in the "force for good" position. Both entrepreneurs claim the moral high ground: O'Leary says that CEOs have a solemn duty to investors to maximize profits, while Lowry asserts that capitalism is not a license to pollute the planet or exploit workers.

Each also claims that his way is the surer path to success. Entrepreneurship is too hard, O'Leary says, to survive distractions like a social mission. Lowry, on the other hand, points out that customers want to buy from--and top talent wants to work for--companies whose values they identify with.

There's one thing these theoretical arguments leave out, though, which is...well, you. Inc.'s founder Bernie Goldhirsh famously wrote that  entrepreneurship is an art form--as much an act of self-expression as writing a novel or composing a symphony. Duty is well and good, and so, of course, is maximizing your odds of success. But to really do the latter, you need a goal that drives you. Not the words on the company's mission statement, but that nuclear bit of grit, known only to you, that gets you through the dark hours of the entrepreneurial soul.

Maybe, in the core of your being, you really do want save the world. If so, go for it: Altruism hasn't held back Method, Toms, Warby Parker, Whole Foods Market, or the Container Store, among many others. But to paraphrase Mae West, goodness isn't the only thing that works. Maybe you need to prove something to the doubters, or your ex-spouse. Maybe you just hate to lose. So be it: Determination never hurt any entrepreneur, even one with the noblest social mission.

All kinds of personal missions are on display in this issue of Inc. Greg Craddock built Patriot Group partly out of patriotism, partly to regain that hyperfocused sense of purpose he had as an Army Ranger. Karen Noseff Aldridge wants to break a rival's suffocating hold on cheerleader gear; it's no accident her company is called Rebel Athletic. And the founders who built Pharmapacks into an Inc. 5000 winner are out to prove not much more than that five guys from Queens and Long Island with street smarts and a cool algorithm can win the free-for-all known as Amazon Marketplace.

None of these entrepreneurs are campaigning for sainthood. And yet they've all created jobs and unleashed innovations that make life better for customers. That's the thing about free enterprise. If you do it right, you save the world in spite of yourself.