But what is it? Hard to say, since the distinction between history and prehistory is that the former is written while the latter isn't. This is just another way of saying that it's very difficult to know what (supposedly) went on in the evolutionary space between animality and humanness. Thus the space is filled with myth, but as we all know, myth does not equate to pure fiction or fantasy; rather, it is truth expressed via these modalities, i.e., in the form of a story.
Really, it's the same with your individual life, so perhaps we can take a cue from that. I don't know how far my earliest memory goes back -- perhaps three years old or so. And yet, we all know that important things happen between 0 and 3; in fact, between -9 mos and + 3 yrs. And something registered memories of what happened, even if the memories are implicit and not subject to conscious recall.
In The Platonic Myths, Pieper says that myths "are played out between 'here' and 'beyond,'" which means that they are primarily vertical where history proper is horizontal. Put another way, myth must be a horizontal narrative about a vertical reality, say, the genesis of the cosmos, the origins of a people, or the provenance of their customs.
Ultimately, all myths have to do with what is beyond or before or after profane time. In other words, myth transcends the conventional categories of past, present, and future, and ventures into the mystery of our origins, our present being, and our destiny, or the First & Last Things in general: the whole alphomega riverrun.
I wonder what Schuon says? "The notion of myth usually evokes a picture of traditional stories charged with a wealth of symbolism and more or less devoid of historical foundation; however, in defining myth one should not lay undue stress on this supposed lack of historical basis, for the function of myth is such that once it has been properly understood the question of historicity ceases to have any practical importance."
Pieper: "The [mythical] events take place outside the historical world that we can understand -- beyond the here and now. For this reason it is only possible to use the language of symbol..."
Again, we are trying to express the higher via the lower, i.e., metaphysical truths via sense images. For example, "because the 'heavenly realm' is beyond our experience we need to have it said, in various ways, what it 'resembles': a banquet, a wedding, a treasure buried in a field, a fishing net, a mustard seed," etc. (ibid.).
The deep past and distant future disclosed by myth are inaccessible in any other way. Again, Origins and Destiny are in principle beyond the limits of science, so don't even try. If you don't understand why science can never disclose these things, then you haven't thought very far or very deep.
Rather, however you manage to do it, the task is "to turn our gaze inwards to the source and origin of both the 'outer' universe of phenomena and of the 'inner' universe of consciousness, to find there the ever-present and eternal simultaneity of what here is seen as a flow of separate events in time; and above all, to fathom the ultimate mystery of our selfhood" (Sri Krishna Prem).
Apropos of Nothing, Pascal has something interesting to say: "it takes no less capacity to reach nothingness than the whole. In either case it takes an infinite capacity, and it seems to me that anyone who had understood the ultimate principles of things might also succeed in knowing infinity. One depends on the other, and one leads to the other. These extremes touch and join by going in opposite directions, and they meet in God and God alone."
"There is a dimension of reality," writes Pieper, "that is simply not attainable by our rational efforts." For the sake of coonvenience we call this unfathomable object O.
Now, "The human self remains always a 'known-unknown,' a mysterious abyss in which more remains unknown than known..." And "there is a kind of infinite or inexhaustible depth in our spirit, due to its openness to the Infinite [O], which cannot be plumbed by our explicit consciousness..." (Clarke).
I can't say it any more clearly than this: "We are drawn out of ourselves, called now to focus on the Great Center beyond us -- also within us, of course -- to take as our own center the One Center and Source of the whole universe, of all being and goodness, the Great Self..."
This is the "deep finality" built into the very nature of spiritual beings. "Thus there is a great double 'movement' [⇅] in the universe of actual being from the Source outward toward creation and from the Creation back to its Source" (ibid.).
This is none other than "the great circle of being, in the exodus of the Many from the One, and the return home again of the Many in the One." This is the rhythm of being, as if "the whole universe itself were one great rhythm of breathing in and breathing out."
A riddle: who is the being that infinitely transcends man?