Say you\'re writing method foo() in class A. foo doesn\'t ever access any of A\'s state. You know nothing else about what foo does, or how it behaves. It cou
No. Never. Static methods should be an exception. OO is all about having Objects with behaviour which revolves around the object's state. Imho, ideally, there shouldn't be any (or very few) static methods, because everything unrelated to the object's state could (and to avoid leading the concept of an object ad absurdum, should) be placed in a plain old function at module level. Possible exception for factories because Complex.fromCartesian (to take a wikipedia example) reads so well.
Of course this (edit: Module-level functions) isn't possible in a single-paradigm OO language (edit: like Java) - that's why I'm such a devoted advocate of multi-paradigm language design, by the way. But even in a language exclusively OO, most methods will revolve around the object's state and therefore be nonstatic. That is, unless your design has nothing to do with OO - but in this case, you're using the wrong language.