NOTES for Dan 2:3
In ancient times all peoples without exception attached special importance to dream-visions. And this was not because the ancients did not know about the mental features of sleep: Greek philosophers already believed that in sleep a person often experiences the same reality he sees while awake, only in another form. The point is that, unlike us today, the ancients also knew something else: the difference between sleep itself and a dream-vision. For them, sleep was exactly what the Greek philosophers said it was: a reflection of "daytime" reality in an altered form.
A dream-vision, however, was perceived as a special spiritual experience, one not determined by everyday reality, which could also be connected directly with a revelation received from higher powers (all the peoples of antiquity agreed that dream-visions sometimes result from the direct action of gods and spirits on human consciousness). Of course, the spiritual soundness of revelations of this kind could always be questioned: the spiritual experience of paganism is ambiguous from the start.
The main point, however, lies elsewhere: unlike simple sleep, a dream-vision was precisely a spiritual experience, not a purely psychic one as ordinary sleep was. And not only because dream-visions could result from spiritual influences on a person from higher (or, conversely, dark) spiritual powers, but also because dream-visions were marked by extraordinary clarity and distinctness. This was also explained, among other things, by the fact that a person in a state of dream-vision was not actually sleeping at all, but was awake; in any case, his self-awareness usually functioned quite distinctly during a dream-vision. And clarity of self-awareness is the main and absolutely necessary condition for every spiritual experience.
If such clarity is absent, a person is, in essence, in delirium or in a half-delirium, as usually happens in sleep. Dream-visions played a role in the Yahwistic tradition as well, although the prophets, for example, had an ambivalent attitude toward dream-visions, considering them a lower form of spiritual life in comparison with traditional prophetic (often ecstatic) revelation, which always presupposed a state of wakefulness, not sleep. Clearly, in speaking against trust in dream-visions, the prophets feared precisely spiritual confusion; they feared that the dreamer, without sorting things out, could be mistaken not only about the meaning of the experience received, but also about the spiritual quality of its source.
And still, in the post-exilic period, in the Hellenistic era, when the Book of Daniel was written, dream-visions began to play a special role in the Yahwistic, or more exactly Jewish, tradition, and above all among visionary apocalypticists. Apparently, this was connected with the fact that the classical prophetic tradition was already in the past in those times, while the need for direct revelation among the people of God remained. That is when dream-visions became the main form of such direct revelation.
But even in those times, of course, experience of this kind was not limited only to the framework of the Yahwistic or Jewish tradition, and the author of the Book of Daniel proceeds from this fact, obvious to everyone. Of course, not everyone could understand the meaning of what had been seen: understanding requires a special spiritual effort, and not everyone is capable of that. But many could see. Regardless of social status, intellectual level, or religious and cultural background. For here almost everything depends on God. And He does not confine Himself to any of the limits so familiar to people.