The state of consciousness of young children and tribal hunter gatherers is termed Original Participation, in Owen Barfield's nomenclature.
Original Participation entails perceiving the outside-world as intrinsically alive and conscious - including things that modern adults regard as 'dead' such as trees, rivers, hills, caves - and toys, books, buildings, cars... The world is seen and felt to be full of beings.
Actually, the child participates in creating this world - in recognising and evaluating the aliveness and consciousness; but the child is unaware of the fact and sees reality as out-side himself; himself as passively a component of that external reality.
The child understands himself simply to see, hear, touch smell and taste reality - he assumes that reality is out-there and that his senses merely give an objective picture of objective reality.
The child is immersed-in an animated world, hardly aware of himself; hence unfree.
(In those cultures which followed hunter-gatherers, the older child or adolescent comes to recognise that his senses are not necessarily reliable, and that different people perceive the world differently. He knows himself as separate from that outside world; and because separate he knows himself as free: free but cut-off, alienated, no longer participating... For Barfield this situation of alienated freedom is seen as a developmental phase in the gradual, incremental evolutionary-unfolding of Man's consciousness towards Final Participation - in which he is both free and also participating.)
To attain Final Participation is simply to return to exactly this child's basic understanding of the world as really full of alive and conscious beings - but this time in full awareness that we ourselves, by our thinking, are participating in the knowing of reality.
In Original Participation the child perceives (sees, hears, feels) the world to be really alive and conscious; in Final Participation we think and we know that the world really is alive and conscious; and that we have participated in making it so.
This Participation is indeed Final because it is the truth; it is the divine way of being.