The philosophy (like many other effective ones) is short.

You are entitled to an opinion
only if you can support it.  

I usually follow this with : Otherwise, shut up!  

While embracing this philosophy has made me wildly successful as a consultant and instructor, it has caused me some problems. The biggest reason for this is the addendum above.

You see, I insist that others must adopt the base philosophy if they want to spew their own opinions in my direction. I am amazed by the large number of people who give opinions without knowing why they believe them. By insisting that they support their opinions I cut many conversations short.

As a result, many consider me opinionated. You'll notice everyone has opinions. It seems that people consider only us who can tell why we hold our opinions as opinionated. I'm ecstatic that people think me opinionated. It means I'm upholding my philosophy well.

Another thing I do is enforce my addendum upon myself. If I don't have adequate support for my opinion, or I do not feel strongly about my opinion, then I withhold that opinion. Because of this, others tend to view me as arrogant. When one is sure of his arguments, then one is apt to expound them.

I guess restraint caused the best back door compliment I have ever received from a co-worker. He was talking during lunch with my boss and some other co-workers (I was not present). He said, "That Coghill is an arrogant S.O.B., but, when he opens his mouth, he sure knows what he's talking about."