With Jung, psychology went from Freud's standard of "sounds good" to anecdotal evidence. It's imperfect, but it's definitely interesting. At least they were seeking out common threads among cases, although they were seeking specific threads and that skewed the conclusion.

The case for dream interpretation on an individualized basis makes good sense. Subsequent essays show why interpretation should be individualized because the the universal archetypes they try to impose on interpretation are often unhelpful leaps in logic. When I dream, my mind is more likely to reference my current situation. It not likely to access the universal understanding of the number four.