President Harry Truman taught us all a great principle of leadership when he famously put a sign on his desk that read, “The Buck Stops Here.” He was answering the tendency of some leaders in his day to “pass the buck,” to refuse to take responsibility and to instead pass blame and obligation on to others. Truman knew that by declaring that he would not pass the buck, that he would take final responsibility, he was defining the culture of his administration.

I have never ceased to marvel at how decisively a leader shapes the culture of his or her firm when they simply determine that they will take responsibility. A kind of peace settles on those they lead. They gain confidence that someone is at the controls, that blame will not be shifted, that decisive answers can be had, and that a culture of decision ownership prevails. The whole firm moves forward steadily as others take their signal from the top leader that courageous decision-making is prized.

By contrast, I have watched firms descend rapidly when cowardice reigns, when no one will make clear decisions, when blame is constantly shifted, and when executives are too busy avoiding the possibility of mistakes to make the reasoned decisions that make for greatness.

There is a scene in one of my favorite movies, Apollo 13, that captures this principle. A crew of astronauts has been readied for a moon landing. They’ve worked together for months. Then, at the last minute the medical staff determine that one of the crew members might come down with the measles during the mission. The commander has to make a decision: either the crew member in question must be benched or, if the commander insists on keeping his crew together, the whole crew will be dropped from the mission.

The commander, played by Tom Hanks, informs his crew that one of them will not be going. When a bit of rebellion surfaces, Hanks—who is playing real life Commander James Lovell—says simply, “This was my call.” That ends all surliness, all bitterness, and all complaint. A decision had to be made. I made it. That’s the end of it. Now let’s get on with business.

What successful leaders know is that every decisive action they take helps build a culture. Be firm, be clear, be reasoned, and be wise and those you lead will be confident, motivated, eager for responsibility, and admiring. Run from responsibility, place blame, and be weak and those you lead will be insecure, uncertain, and fearful.

Decisions are the building blocks of great leaders. Welcome them, ponder them wisely, make them and stand by them. This will spill over into your firm and fashion a culture of eager leadership and healthy ownership.

Thank you, Mr. Truman, for setting the example.