Human consciousness is divided into three sequential phases: Original Participation, the Consciousness Soul and Final Participation.
This sequence is primarily concerned with human society, or civilisation through hunter gatherer, agrarian and industrial phases and pointing at the destined future - but also corresponds to the development of Man from birth to mature adulthood.
Thus the consciousness of Original Participation can be seen both in the 'childhood of Man' (the earliest, simplest and most spontaneous society: the hunter gatherer life), and also in each Man's childhood.
I became extremely engaged with understanding the hunter gatherer mind some twenty years ago - by immersion in all sorts of books on the subject; both by leading twentieth century academics (mostly anthropologists) who lived among such people (or among those who had recently been hunter gatherers) and also by looking at some examples of 'first contact' literature from previous centuries when a variety of people - e.g. explorers, missionaries - described their encounters with hunter gatherers.
My interest was then focused on spontaneous animism; or the way in which hunter gatherers - and young children - interpreted the world 'anthopomorphically', or socially; in terms of being a collection of person-like agents. So large animals (such as the bear) or environmental objects both living (such as a tree) and 'non-living' (such as a mountain) would be understood as persons, each with a character, motivations, desires and intentions.
Thus, for the hunter gatherer the whole world was social; a web of relationships. And if we can remember and introspect about our own early childhoods, we can perceive that it was the same situation for each of us; we used to see the world as social, as full of living and conscious entities.
(This may also re-emerge in altered states of cosnciousness - such as the 'paranoid' delusions of self-reference in psychotic illnesses, or in some types of brain pathology, or some types of drug intoxication. The social perspective seems to be something of a default.)
The perspective of Barfield brings a further aspect to this subject; which is to notice that for the hunter gatherer the Self was much less developed and distinct than it is for us (living at an advanced stage of the Consciousness Soul); the individual hunter-gatherer is not, therefore, very aware of himself as an individual - does not perceive a line of demarcation separating himself and 'the world' (when 'the world' includes both the society of other people, and the society of significant entities in the environment - bear, tree, mountain etc.).
The hunter gatherer participates in the world because he perceives no separation between himself and the world; and much the same applies to young children even nowadays. But as civilisation developed, grew, became specialised... each Man separated from the world, and perceived life as himself one one side of a line, and everything else on the other side - losing the sense of participating in the world, and feeling more-and-more like a detached observer.
Indeed, matters have reached such a point, that we even feel detached from our own thoughts - that is, the thought in our minds are not regarded as the same thing as our-selves.
The disadvantages of the modern condition are obvious enough - alienation from life, and despair. But the advantages were also perceived by Barfield, drawing from the early work of his master Rudolf Steiner. The key word is freedom. By separating our perceived self from the world, the self becomes free.
The hunter gatherer is hardly free, because he hardly feels himself separate from the flow of the human and other environment in which he lives; and much the same applies to the young child. Modern Man in the Consciousness Soul phase is, by contrast, in a position in which he may becomes free, may be able to stand apart from the influences on his life; and consciously, deliberately, in full self-awareness exercise his divine creativity as a source of original thought, and potentially other actions as well as thought (although Steiner clearly described that it was in Thinking that Man primarily was free).
The equivalent phase to the Consciousness Soul for the developing Man is adolescence; when a man becomes conscious of himself (self-conscious) apart from other people - and this becomes 'a problem'.
As for growing-up into Final Participation; Barfield (and Steiner) would say that this seldom happens in the way that it should - it happens to few people (and only partly and intermittently) and has not yet happened to any human society. Final Participation would be a state of consciousness which retains the autonomy and freedom of The Self (which emerged during the consciousness soul) but returns to a felt-participation-in The World; but a participation of a new type.
The way I envisage Final Participation is that we participate in The World through loving relationships; in the sense that only an autonomous self, distinct from other selves, can love. And this means that in order to participate we must (again) recognise the world as wholly alive and conscious - just as was the case when we were young children, or as did hunter gatherers.
So, we have much to learn from hunter gatherers, and from young children - but not so as we can go back to that form of consciousness, but so that we personally - and also our modern societies - can go forward to Final Participation in which we would have 'the best of both worlds': both and simultaneously the felt-and-lived engagement with the world typical of hunter gatherers and children, and also the freedom and distinct individuality of the Consciousness Soul.
Final Participation, I would therefore regard as the destiny of each Man, and of Mankind as a whole - if we choose to accept it.