What is orthogonality?

[Karen Lanrap]

Bill Baxter wrote:

> In the semantic sense his example of 
> overloading functions by number of paramters versus using default 
> parameters is exactly 100% UN-orthogonal.

He says something similar himself:
| You need to pick one of them, even though both are good.

But your question is still legitimate, because of the turing 
completeness of general purpose languages every claim of 
orthogonality has to be evaluated on some level of abstraction above 
the needed features for turing compatibilty.

If there is no agreement on the level of abstraction there is no 
absolute orthogonality. All one can state then is, that some feature 
is relatively orthogonal to some other feature.