Leadership is practically a cottage industry, and content on leadership is literally everywhere.

And that's a good thing. Every time someone like Elizabeth Holmes or Bernie Madoff comes on the scene, we are reminded that true leadership is in short supply.

Maybe one of the reasons is that we talk a lot about leadership, but not enough about the traits and actions that make a leader. Leadership, after all, is the fruit of the tree, not the tree itself.

And one of the most important--if not the most important--roots of that tree is courage.

How much content do you see that focuses on courage, or attempts to define courage?

Very little.

Too little.

That's really, really unfortunate--because courage is the foundation of leadership.

Sure, you say, courage is great--but what about knowledge and intelligence?

Those qualities matter, but no one can argue that a lot of smart, intelligent people have failed miserably as leaders.

What about toughness?

Toughness has a pretty subjective definition--and I've seen people who value toughness above all else struggle to adapt when a situation calls for a softer approach.

What about being a hard worker?

Committing yourself fully to the cause is essential, but I've been around individuals who defined leadership as the willingness to work 27 hours of a 24-hour day. Unfortunately, this approach to leadership drains the aspiring leader, and fails to inspire those who hope to follow that leader.

Put another way, I looked at a former boss of mine who worked that type of schedule and concluded that I wanted to be nothing like him, which inevitably lessened his influence to me.

Knowledge, intelligence, toughness, hard work--those qualities and others are, at varying levels, important components of leadership.

But above every other quality of leadership, courage is what separates real leaders from people with the titles and trappings of leaders.

However, before we define what courage is, let's define what courage isn't.

Courage isn't peeking around the corner with one eye toward a calculator, trying to figure out when the odds are safest for you to step out and say something.

Courage isn't safe.

Courage isn't managed risk.

Courage isn't a math problem.

Courage isn't working the odds.

Courage isn't a safe bet.

Courage isn't data-driven decision making.

Courage isn't a statement from your spokesperson.

So what is courage?

Courage is stepping up and standing out--often by yourself--when you know something needs to be said.

Courage is leaping before you look in the name of a greater good.

Courage can be lonely.

Courage requires thick skin.

Courage requires you to have something to lose, and the willingness to lose it.

Courage might mean lost jobs, lost "friends", lost opportunities.

Courage is being able to proudly tell your kids and grandkids that you didn't wait for someone else's permission or the math to add up in your favor before you stood up for what you believed in.

Courage is leadership.