There are two types of theories: event theories and construct theories. Both are used to explain some phenomenon that you've observed. Event theories can be measured; these types of theories can be verified and proven. You can judge the accuracy of an event theory.
Construct theories are intangible abstractions; it makes no sense to speak of "proving them." Instead, construct theories are evaluated in terms of their usefulness.
You can't judge a construct theory to be accurate or not. That's mixing apples and existentialism. An apple is a thing; existentialism is an abstraction.
For instance, I can prove all sorts of things about your brain using simple electricity or complex medical imaging devices. But I can't even prove you have a mind. Mind is an abstraction; there's really no such thing. It's just an idea, a concept. But it's a very useful one.
[Source: Andy Hunt - Pragmatic Thinking and Learning]