For a while now I've been arguing that we shouldn't look for consciousness in the brain. We haven't found it there, and we won't. Not because consciousness happens somewhere else, in the soul, say, or in the environment, or in the collective. But because consciousness isn't something that happens; it is something we do or make. And like everything else that we do, it depends both on the way we are constituted — on our brains and bodies — but also on the world around us.Sidestepping the actual question of what consciousness is, I think this discussion has implications for fiction writers. (Well, everything has implications for fiction writers.)
Literature and literary characters give us more direct access to other minds than we have in everyday life. At least we seem to have access, in the form of other people's interior thoughts. On the other hand, this access is limited to what can be expressed in verbal language; and the other people are, at least to some extent, fictional.
I won't wade into the morass of how much language itself creates or forms consciousness. But we do experience a sort of merging of consciousnesses when we read. The author's words steer our minds in directions they might not otherwise go. Her language, for a time, becomes ours, though what we see and feel through that language can't be exactly what the author saw and felt when she was writing. We're drawn in by generalities, a shared language and similar broad-strokes experiences (love, loss, fear, ecstasy). But it's the edges, where the differences are negotiated, that give art life.
About character specifically: It seems to me we could think of characters as consciousnesses, by which I mean ways of seeing and being in the world, which overlap in general ways but not in specifics. I think I've too often pictured my own characters as different, atomized mixtures of my own consciousness (which I'm sloppily eliding here with personality): That one has more of my prickliness and less of my confidence; this one embodies my secret desire to become a hairdresser. But I haven't thought enough about how these guys relate to each other as consciousnesses.
In other words, just like us real people, characters should be aware that others have minds, and be equally aware that they can't quite reach them. They are as alone, and as connected, in their world as we are in ours. And moments when consciousnesses seem to touch and interact--as when an author suddenly shows us an entirely new way of seeing--should be as amazing for characters within the novel as they are for us on the "outside."