Magic has a subjective component--the intention, desire, or willpower of the practitioner--that is explicitly excluded from scientific experimentation.

I disagree - I think that although science ought to be practiced like that, it often isn't - people frequently go into experiments with a very clear idea of what they'd like out of them (indeed, to develop an experimental hypothesis is to make a fairly fundamental statement about the desired outcome).

It's funny that you should post about this today - I'll write a poll in a sec that will explain why.