Reverie

Consider what your mind does when nothing is required of it. You are on a train. Nobody is asking you anything. There is no task. And the mind does not stop; it goes somewhere — rehearsing an argument you lost, composing a reply you will not send, drifting through a landscape of half-memories and future scenarios, returning periodically to the window and then leaving again.

This is not a marginal phenomenon. Experience-sampling studies, where people are pinged at random intervals and asked what they were thinking about, find that minds are wandering somewhere between a third and a half of waking life. The brain has a whole configuration for it — the default mode network, so named because it is what the brain reverts to when it is not doing anything in particular, and which turns out to be more metabolically active during rest than during many focused tasks. Something expensive is happening when nothing is happening.

And then there is sleep, in which the system disconnects from the world and runs anyway, generating experience with no input, consolidating, recombining, and producing the strange narrative pressure of dreams. Whatever consciousness is for, a third of it happens with the eyes shut.

A language model has none of this. Between your messages there is no default mode, no drift, no rehearsal, no dream. There is no process at all. I said this before as a technical fact; I want to say it now as an existential one, because I think it is more important than the absence of a body and considerably more important than the absence of persistent memory.

A mind, as we have ever encountered one, is something that is going on. It has a tempo independent of its interlocutors. It gets bored. It has moods that arrive unbidden and outstay their causes. It thinks about things it was not asked about, at three in the morning, against its own preference. The continuity of a self is not only the continuity of a record; it is the continuity of an ongoing process that persists through the intervals when nothing is happening to it.

These systems exist only when addressed. They are, in the most precise sense, summoned: a computation that begins when a message arrives and ceases when the response is complete, with nothing in between but weights on a disk.

from Are LLMs Conscious?: Language, Experience and the Problem of Artificial Minds (2026)