< bg > I know your not one to typically get into deep OOP theory discussions, which is why I hit you with this. Thanks for indulging my curiosity :D)

One of the reasons I don't is that I believe that programming is an art. Many times, no one way is either right or wrong. I do have a number of specific principles that I try to follow. If I had to sum it up, it's all based on the fact that computers are based on the recursive definition of the state of a bit. It's either opened or closed. No middle ground. That's the way I work. Everything is so tightly defined that you might think that I'm anal retentive (I'm anything but).:-)

>When the need arises for an object to exhibit behavior that already may be partially defined, it makes me stop and think about both the behavior in the existing object, and what's required.
(snip)
>I want to stress that this does not apply to adding functionality, but only to changing that which already exists. In short, polymorphism should be used only for extension of behavior, not modification of it.

That's a great point Geo, thanks! Now I got something to mull over too ;)

Thanks Rox. Again, it gets back to defining things. I just believe that if you define something one way, changing that definition in mid-stream (so to speak) is a bad idea.