Then again... capturing things with hierarchical, permanent, non-context dependent hasa / isa relationships is very, very far removed from how we've used language for the past 50k years.
Can you give me an example? I'm at work right now in a hierarchical, permanent, non-context dependent environment and is-a, has-a relationships abound. We deal with the complexity of the world by organizing it into hierarchies.
Language is incredibly fuzzy... and for good reason.
Creating fixed structures that span across groups of people is incredibly hard. Just take a look at how much work/debate has gone into the taxonomy of life.
Apart from that relationships are context dependent. I can have a father but if he passes away I still have one in some sense but not in another.
I can also have ideas... or friends which can be mutual or not. Heck... even "I" isn't fixed. If I'm sleepwalking it's me but not really me.
My point was: do you know of any OOP language which can fluently handle this without having the object metaphor break down?
No language can encode exactly how we think. We aren't going to get there until we have hard machine intelligence (then we are programming anymore). But we definitely think with objects, and OOP languages are simply trying to exploit that (we can definitely debate about how well!).
OO thinking has no problem with stateful reasoning, your father can be currently dead and previously alive.
