Editor's Note: The Zen ZoneIn this issue, we take an in-depth look at leadership -- and what it means to entrepreneurs.

The L-word. Who doesn't get a little tingly when the subject comes up? Wait, not that L-word--the other one:leadership. Yes, leadership is one of the most hotly discussed, debated and proselytized words in the lexicon of business. And there's good reason to keep tumbling the topic around: Great companies have great leaders--but a bad leader can tank a great company.

Scroll through the leadership section of any online bookstore and it's easy to see that theories on the subject come and go faster than location-based social sites. And those theories tend to mimic the zeitgeist.

In the 1980s, a leader was defined by power and control. An absolute must for all great leaders was immersion in--and subsequent quoting of--Sun Tzu's The Art of War. This was not optional. If you hadn't read Art, if you didn't spew forth the lines of wisdom regarding battle, you couldn't be considered a great leader. You were thought weak, powerless and untrustworthy. Greed was good then.