Prophetic Dreams

The Bible mentions quite a few prophetic dreams. The current book I'm reading -- Maimonides' Guide for the Perplexed -- contains some passages showing the author had given extensive thought to the topic of prophecy, vision and dream.

Despite Maimonides' acknowledgment that the will of God is required for prophecy (Part II Chapter 32), there are times when his thoughts run along nearly naturalistic lines: 

Prophecy is, in truth and reality, an emanation sent forth by the Divine Being through the medium of the Active Intellect, in the first instance to man's rational faculty, and then to his imaginative faculty; it is the highest degree and greatest perfection man can attain; it consists in the most perfect development of the imaginative faculty. (Part II, chapter 36).

Both philosophy and prophecy, in Maimonides' view, are human perception of the Divine Intellect -- the philosopher being limited to the rational faculty, while the prophet has also developed the imaginative faculty. As for dreams:

In Bereshit Rabba (sect. xvii.), the following saying of our sages occurs:

Dream is the unripe fruit of prophecy.

This is an excellent comparison, for the unripe fruit is really the fruit to some extent, only it has fallen from the tree before it was fully developed and ripe. In a similar manner the action of the imaginative faculty during sleep is the same as at the time it receives a prophecy, only in the first case [the dream] it is not fully developed, and has not yet reached its highest degree. (Part II, chapter 36)

Maimonides believed that these prophetic visions and dreams were things for which someone can train and prepare himself. In his comments on what makes a person fit to receive a prophetic vision or dream, this one passage particularly caught my eye:

... all his desires must aim at obtaining a knowledge of the hidden laws and causes that are in force in the Universe; his thoughts must be engaged in lofty matters; his attention directed to the knowledge of God, the consideration of his works, and of that which he must believe in this respect. (Part II, Chapter 36)

Our dreams naturally tend to follow the aim of our desires, and what engages our thoughts, and that to which our attention is directed. Wouldn't that tend to cause dreams on those topics? Maimonides acknowledges that there are people who dream things that are not fit to be called prophetic dreams, despite the dreamer's insistence.  Still, in Maimonides, the line seems thin between a dream of Divine Things and that "unripe fruit of prophecy".