Too often leaders tend to hire those in their own image. How many times have you heard a leader say, "you remind me of me when I was younger". This great quote sums up why many leaders fail. They have no one in their business lives to disagree with them. If you are a leader, it starts in the interview process. A true leader is never afraid to hire people better and smarter than they are. Ask questions to determine if this is simply a yes man, or someone who will challenge your thinking. Someone who can make your ideas and leadership better, not maintain a status quo.
If your a follower, understand that you have a duty to add to any idea in a collaborative process that builds improvement or greater value, even if the idea or concept comes from your boss. However, there is a respectful way to disagree, and do not try to become one of those "disagreeable cusses" who always has a different point of view.
The quote is always true, when two men in business always agree, one of them is unnecessary. Too often it is the leader who is the one not needed and many times it is simply because he hired a team of people he knew would always agree with him.
As you push your square rocks uphill today, be on the look out for those who can contribute a different point of view while maintaining the common goal of success for your vision.