intermundium

But even the sound of our own or another's voice takes them out of that lifeless, twilight, realm of thought, which is the confine, the 'intermundium', as it were, of existence and non-existence.

Literary Remains, Volume 1 Samuel Taylor Coleridge 1803

While the former rest content between thought and reality, as it were in an intermundium of which their own living spirit supplies the substance, and their imagination the ever-varying form; the latter must impress their preconceptions on the world without, in order to present them back to their own view with the satisfying degree of clearness, distinctness, and individuality.

Biographia Literaria Samuel Taylor Coleridge 1803

While the former rest content between thought and reality, as it were in an intermundium of which their own living spirit supplies the 'substance', and their imagination the ever-varying 'form'; the latter must impress their preconceptions on the world without, in order to present them back to their own view with the satisfying degree of clearness, distinctness, and individuality. "

The Life of Samuel Taylor Coleridge 1838 James Gillman