This is something I'd like a better understanding of. snegledmaca had an interesting idea about it... I'd like to explore it as well as other explanations and ideas.
extraverted intuition = internal statics of objects
extraverted sensing = external statics of objects
extraverted logic = external dynamics of objects
extraverted ethics = internal dynamics of objects
introverted intuition = internal dynamics of fields
introverted sensing = external dynamics of fields
introverted logic = external statics of fields
introverted ethics = internal statics of fields
So internal is intuitive and ethical, external is sensory and logical.