Well said, and some great quotations. I confess I haven't read any Hesse, but I really should. Some other commenters have pointed to some complications in the case of animal consciousness, so I should probably write more on this connection between consciousness and alienation, to try to clarify this aspect of the existential predicament.

"The insistence upon familiarity" is an interesting way of putting Kant's point about phenomena, I think.

And it's true that we can imagine the opposite of alienation. Perhaps we even have an unconscious sense of this unity, based on our tree-like, Edenic experience in the womb. But whether those unifying conceptions testify to a solution to the alienation of being a person, or whether even those conceptions express alienation in a distorted form is another matter.

As I say about Judaism, Yahweh seems a symbol of social alienation. He's supposed to unite everything at the end of history, but that yearning indicates a prior state of alienation, and Yahweh's hiddenness from nature (or from idols) mirrors Jews' detachment from dominator societies.

The concept of nature or of the universe is likewise supposed to be unifying, as dictated by the pragmatism of methodological naturalism. But that pragmatic presumption is itself a sign of alienation: we assume nature is unified and that there are no miracles because we're set upon conquering all wild territories, and we'd rather not face any insuperable difficulty in that endeavour. Just as hunters are implicitly detached from their prey, scientists are detached from nature in assuming that nature is wholly subject to domestication.