Understand that prophecy wasn’t the same experience for each and every prophet; there were degrees, one might even say different “flavors” of it. For despite their decidedly gifted status, some prophets experienced somewhat prosaic prophecies, while others — like Isaiah whom we’d cited — were privy to great and broad, cosmic revelations.
Though Ramchal doesn’t enunciate them here, we’re taught in fact that there were twelve degrees of prophecy. (We’ll be drawing from Rambam’s “Guide for the Perplexed” 2:45 here, from Hilchot Yesodei HaTorah 7:6, and from Rambam’s Commentary on Perek Cheilek).
The first and second degrees are termed “divine inspiration” and “the spirit of holiness” respectively, rather than prophecy per se. Divine inspiration is characterized by being moved to participate in important things, and the spirit of holiness is characterized by having a sense of being overtaken by “something” or another that moves the prophet to moral insight or civil action. Ramchal underscores the fact, though, that these are definitively perceived as being Heaven-sent by the prophet, and not simply a private insight of his own, and that he understands the implications of what he’s sensing.
The other degrees, which do fall into the category of out-and-out prophecy, are as follows in ascending order: seeing a prophetic vision in a dream, hearing things in a dream without seeing a speaker, being addressed by a human in a dream, being addressed by an angel in a dream, being addressed by G-d’s voice outright, having symbolic visions while awake, hearing voices in a visionary state while awake, being addressed by a human form in a prophetic vision while awake, and by being addressed by an angel in a prophetic vision while awake. The ultimate degree is unique to Moses, as we’ll soon discover.
Whereas they received their prophetic visions either in a dream or in a trance, Moses received his prophecies in a waking, conscious state. While the other prophets would grow faint when they prophesied, shivering and frightened, Moses experienced none of that. Where the others would often have to wait for days or even years for a prophecy, Moses could prophesy at any time. Though the others received their prophecy through an angel or a vision, Moses envisioned clearly. And while the others had to prepare themselves for prophecy, Moses was always attached to G-d, and thus never had to prepare himself for that.
Rabbi Yaakov Feldman has translated and commented upon “The Gates of Repentance”, “The Path of the Just”, and “The Duties of the Heart” (Jason Aronson Publishers). His works are available in bookstores and in various locations on the Web.