We're not studying Johnson, by the way, but he does have some interesting things to say about it ... I personally think his stuff is too preachy and really is a bit of pop-psychology.
This is an interesting read - it is a sermon from the UUYO church in the US. He has some great things to say about the shadow and the collective unconscious. Really well written.
This is a film that tries to portray the tumultuous relationship between Freud and Jung ... might be worth watching to get your head around these important guys. Please keep in mind that this is an artistic interpretation of real people and events!