Sure, once there is a relationship you can make pretty tree diagrams, but that is again, based on perspective.
And just as a draftsman will use a picture to create a piece of machinery, we can chart out
software to ensure its cohesiveness and viability.
If you find that the system you're developing is too mutable, it may be that you're observing several different, but interrelated systems which are part of a larger whole.
So, theorhetically, is manipulating an objects inheritence based on how it is currently being percieved, a worthwhile cause for meditation?
This would be the object oriented version of GOTO spaghetti code.
Further, I seem to remember that part of perl objects get memoized by the compiler at some point in time (methods? ->can calls?), so horribly mutating an object like this might not do what you want, depending on what you've already done to it.