After studying scores of great thinkers like Leonardo Da Vinci, I think I've stumbled upon what really set them apart from the rest of the folks living (and thinking) at the same time.

It's remarkably simple. They learned how to entertain a thought.

Aristotle said, "It is the mark of an educated mind to be able to entertain a thought without accepting it."

Hmmm. To entertain a thought without accepting it.

We need to do that. Everyone needs to learn how to be good host or hostess to new ideas. In fact, our goal should be to become the Martha Stewart of mental entertaining!

What if you treated a new thought like a guest?

It's easier to think about mental entertaining if we put together a to-do list, just like Martha. Here it is:

#1 Make the first move. First of all, you issue an invitation. Nothing fancy. You don't have to make any major investment or lifelong commitment. You're simply inviting this person in.

It's the same with initiating the entertainment of an idea. You might see a quote on the side of a bus somewhere, and decide you'd like to explore that concept more deeply. Or, maybe you find yourself bumping into the same topic all the time, and so you make up your mind to learn more about it. Either way, you need to be ready to initiate the process. Don't hide--you won't meet new ideas if you scurry away whenever the doorbell rings.

#2 Prepare. Uh-oh. Your house is a mess. You'd better do some cleaning. You're not really trying to impress, but hey, you could certainly do some sprucing up and get the place looking neat and inviting.

Prepare for a new thought in the same way. Make some space in your mind to think about something new. According to Deepak Chopra, the well-known author on health and longevity, the average human has 60,000 thoughts a day. Pretty impressive? Well, here's the kicker: 57,000 of those are the same ones you had YESTERDAY! Now that's some serious clutter! Get rid of a few of those dusty old thoughts and make room for new ones.

#3 Offer a warm greeting. When your new guest arrives, be warm and inviting. After all, you're hoping to start a friendship. Put your best foot forward.

It's the same with an idea. If you face it with skepticism, fear or detachment, you won't be entertaining it for long. You'll be eyeing your watch, yawning, or looking for a way to end the discussion early. You've got to be open and full of anticipation to prepare an environment in which new ideas will be explored and integrated fully. Just as it's no fair making lame excuses or having your friend call to interrupt the visit, it's also cheating to cut out too soon when it comes to entertaining an idea.

#4 Make introductions. This is the big one. You would certainly introduce your guest to everyone at the party, with a special effort to connect them to those with whom they may have something in common.

Any new idea you consider will be more likely to be welcomed if you actively and intentionally introduce it to your other ideas and interests. Look for unusual and inspired pairings. How does it fit? Where does it fit? DOES it fit? You won't know until you try.

Picture Leonardo Da Vinci's mental entertaining. His new idea, Human Flight, arrives, and immediately Leo sets about introducing him to others. "Human, meet my good friend, Engineering, and his lovely wife, Fabric Design. Oh, and have you met Bird Anatomy? She lives just around the corner from you. Oh, Dr. Entomology has arrived! Listen, Dr. E is absolutely brilliant, but a bit hard of hearing. Ask her about her recent work on the wings of insects! Now, you all make yourselves comfy and I'll go get some more wine."

What happened at that party? Leonardo threw these ideas together, and BAM! What emerged was the idea for a perfectly designed parachute as well as a remarkable helicopter--hundreds of years before the Wright brothers started building their flying machines! Talk about a soaring success! Don't you wish you'd been there?

#5 Offer the best seat in the house. You usually sit in that nice chair there by the fireplace, but when a special guest comes over, you graciously offer it.

When you are entertaining a new thought, give it the consideration it deserves. Every time you think a new thought, your brain is actually creating a new neural pathway. It's like a jungle in there, full of nerve endings and ganglia and all kinds of connections. Help it along. Make it comfortable.

Once you've considered an idea, that pathway is there. All you have to do to keep it "live" is to keep going down that path often enough to clear the trail, but not so often that it becomes a rut.

#6 Listen, inquire, and show interest. Ask questions. Dig a little deeper. Find the connections to other people, places, and activities. Learn as much as you can about your new idea.

#7 Relinquish control. Just like when you introduce guests to each other, you should not try to control the outcome. Some guests might hate each other on sight, while others click instantly. People might argue, or a married guest might sneak off to a back room with someone other than their partner. Anything can happen!

That's not up to you. You're having this party to offer an opportunity for people to connect. Make introductions, insert a few comments, smile and acknowledge everyone, but for the most part, just let things happen. Don't direct the flow of ideas.

#8 Leave room for future possibilities. Even if you decide this guest of yours is insufferable, you don't want to burn any bridges. Be gracious, and be glad you were excellent enough to offer the invitation.

You're not going to like every idea that comes your way. And you might not find any other interest or idea that connects with it initially. That's fine. You need to develop the ability to recognize useful concepts and distinguish valuable and valid ideas from those lacking a strong foundation. That's what critical thinking is all about.

But you also need to file that idea away so that you can look it up if and when you DO meet a likely candidate for another gathering of thoughts.

There is a great deal of room for different styles of mental entertaining. Maybe you're best at dealing with only two ideas at a time, or maybe you want to throw a huge bash and welcome all comers.

Entertain in whatever style suits you. Tete-a-tete or bacchanal--it doesn't matter, as long as it's happening.

Learn how to entertain a thought. With a little effort, you'll become a perfect host or hostess to new ideas that come your way. And guess what? You'll have no hangover, no cleaning up, and no regrets.

Party on!