Last Saturday I read an interview in the Wall Street Journal with Tim Geithner. Geithner was Secretary of the Treasury during the 2009 financial crisis, and recently published a book describing his experience trying to lead the country through this difficult financial period. After discussing the financial crisis, the interviewer asked Geithner if he could point to any lessons he learned during the crisis that would apply to other walks of life.

His response really made me think, and I’d like to share it with you. Here’s what he said:

Make sure you surround yourself with people who will disagree with you. Make sure you have competition in diagnosis around you all the time. Make that an ongoing, relentless effort. If you do that, and put aside the concerns of how your actions will be perceived and how you will be criticized, you’ll be in a much better position to sort through all of the bad choices you face. It’s really important to make sure people feel they can disagree with you.

This statement made me think of the best-selling book Team of Rivals by Doris Kearns. In this book, Kearns describes how Abraham Lincoln surrounded himself with advisors who thought much differently than he did. In fact, the advisors he appointed were often from another political party, and in some cases had run against him for political office. They weren’t friends, and in fact they were often political enemies who at various times tried to sabotage him. However, Lincoln knew that he would make the best decisions, and be the best leader for the country, if he surrounded himself with people who thought differently than him, disagreed with him, and were even hostile toward him. He knew that the decisions that came from this body of advisors would be far superior to decisions that came from a body of advisors that all liked each other, got along with each other and thought like him. Although it led to numerous conflicts, this approach proved successful for Lincoln.

I’ve seen this work in our hardwood lumber business at Baillie. Over the last 25 years, we’ve had people in leadership positions who think differently and are not afraid to disagree with each other. Although it sometimes makes things less comfortable and leads to conflict and stress, there’s no doubt that we make better decisions, and ultimately have better strategies, when we have this diversity of approach and opinion. It’s not about being friendly and cordial, but about making the right decisions.

Even if you’re not in a leadership role in an organization, this principle can still help you. In your personal life, if you surround yourself with people that think like you, act like you, and are like you, you’ll probably have a stress-free, peaceful existence. The only problem is that you probably won’t grow, won’t be tested, and won’t increase your ability and capacity to do whatever you’re called to do in life. On the other hand, if you surround yourself with people who provoke you, who disagree with you, who challenge you and even make you mad, you’ll be on the path to growth and personal improvement.

So whether you’re leading a large organization or just thinking about cultivating a couple new friendships, think about surrounding yourself with people who think differently than you.