Leaders should be intelligent, right? I mean, it doesn’t always work out that way, but that’s kind of the ideal. We want our leaders—community, corporate, political—to be intelligent.

But what kind of intelligent?

There are some leaders who know everything there is to know about their industry. Other leaders have read dozens—maybe even hundreds—of books about leadership. Some leaders are particularly strong in emotional intelligence. These are all good things. But I would argue that there is another kind of intelligence that eclipses these.

In fact, I think it’s the most important kind of intelligence a leader can have.

I think a great leader needs to have the kind of intelligence that Shakespeare had.

I just finished reading Bill Bryson’s wonderful book, Shakespeare: The World as Stage. I love this book (I love pretty much all of Bryson’s books). Partially because I love Shakespeare (I was, after all, an English major for a few years), but mostly because I love Bryson’s insight into Shakespeare and his times.

There was one particular insight that really caught my eye. Bryson was analyzing Shakespeare’s particular genius. Here’s what he said:

“Shakespeare’s genius had to do not really with facts, but with ambition, intrigue, love, suffering—things that aren’t taught in school. He had a kind of assimilative intelligence, which allowed him to pull together lots of disparate fragments of knowledge….”

Assimilative intelligence.

That’s it. That’s the one. That’s the most important kind of intelligence a leader can have.

Assimilative intelligence is the ability to, as Bryson says, “pull together lots of disparate fragments” to arrive at a result, a decision, a new whole. Assimilative intelligence is at the root of creativity, and it should be at the root of leadership.

Leaders are bombarded with information from multiple sources—much of it contradictory. The world—despite what politicians and the media might have you believe—is not black and white. Serious issues, whether in politics or in business, cannot (and, I would argue, should not) be summed up in neat, eight-second sound bites.

The world—including the world of business—is complicated, messy, and, at times, contradictory.

A leader needs to be able to look at all the pieces of the puzzle; he or she needs to be able to see all sides of the situation. In short, a leader needs to be able to assimilate all of the disparate elements in order to understand the big picture—and to make an informed decision.

F. Scott Fitzgerald once said,

“The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function.”

That’s also the test of a first-rate leader.