@kennethamy,
His psychological types are much less significant, I think, than his theory of archetypes.
What makes Jung a great and significant thinker, in my opinion, is precisely this theory of archetypes.
The mind has an inherited structure. Humans are programmed, if you will, to respond emotionally to certain myths, certain symbols. The same kinds of myth appear in isolated cultures all over the world, and also in our dreams.
I feel that meta-physicians have infused these myths into their systems. Which is what I think Hume missed about their value. Humans want more, I think, than the practical.