I saw a demonstration once that really amazed me. A hospital I worked with had developed methods for training dogs to sniff out cancer in the human body. I have to tell you that I had never seen anything like it.

Now, I’m a dog lover and I’ve done a great deal of reading about dogs. When my grandfather retired from the Army, he trained Samoyeds and taught me a lot about man’s best friend. I learned, for example, that while a human being steps into a kitchen and can smell chili cooking, a dog smells each individual ingredient of the chili—the tomatoes, the beef, each individual spice, etc. Our canine buddies really are amazing.

I did not know, though, that dogs can be trained to smell certain sicknesses in the human body. Yet in the demonstration I’ve mentioned, dogs located cancers in patients accurately every time. It was moving and encouraging.

I mention this memory because it highlights an instinct that great leaders must possess. They have to be able to identify the cancers within their organizations. They must possess the fine-tuned-senses to know what is cancerous and thus deadly to their firm and what is not. Their leadership and their organization’s success depends upon it.

Let me give you an example of how this works. Duane has been demoted because of poor performance and he’s smarting over it. Still, he is a good man, he’ll learn and rise again. He’s not the kind of soul who will try to infect others with his disappointments.

Damon, though, has endured the same demotion, but he is intent upon revenge. He talks about his perceived mistreatment, he enlists others in his emotions, and he focuses his seething animosity upon the boss.

Damon is unleashing a cancer in his company. It can grow, it can disillusion hundreds, it can erode productivity, unity, and joy on the job. Duane, however, will only make the firm stronger. His transparency and overcoming determination will only cause him to make the company better.

The great leader knows the difference between these two scenarios. Like a master chef, he knows how to sprinkle inspiration into Duane’s soul but have the challenging, “get it together” confrontation with Damon. One man is toxic, the other a well of good. A great leader knows how to build with the one and either help the other make a healthy turn or, if necessary, root him out.

The art of detecting cancer—when it comes to leadership—is simply the art of pondering the present in light of the future. What will the current situation, unchecked, produce in two weeks? Two months? Two years?  This question is your cancer detector. It is not designed to make you paranoid and suspicious. It is designed to provide you with a tool of analysis that exposes what present trends continuing will mean for your firm.

Every week, ask the cancer question: Is there anything happening which left unchecked will devour the good of our firm? If the answer is yes, then proceed wisely and skillfully. But proceed. Don’t let neglect of a cancer be your death.

That’s it. Have a great weekend.