Boundary between you and the outside world

Chapter 8 endnote 20, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

The classical view [...] draws hard boundaries between you and the outside world. [...] So, by implication, your mind would be completely inside you and the world completely outside you. [...] Different versions of the classical view frame this boundary differently

In basic emotion theory (one flavor of the classical view of emotion), your response to the world is thought to be instinctual. A snake slithers past your feet, and you respond in fear. You can regulate the fear either by avoiding the snake altogether, or changing what it means to see a snake after the fact. But initially, snake equals fear. Although William James did not hold to a classical view, he did describe instinctual responses in a very compelling way, “the nervous system of every living thing is but a bundle of predispositions to react in particular ways upon the contact of particular features of the environment….”

In classical appraisal theory (another classical view), you first “interpret” the stimulus before you respond to it.

Both flavors of the classical view are stimulus → response theories, with a firm boundary between you and the world. First you perceive (then you evaluate, according to classical appraisal theory), then you respond.