Bayesian brain theories are more "in vogue", along with various other theories saying that the brain does some forms of statistical and causal learning and inference.
They don't preclude it, but they didn't happen to include it in our particular history. In particular, in the evolutionary history of the brain as an energy-optimizing controller of the body, a "System 1" would have been selected against extremely early on, when it directed the internal organs to act according to "heuristics" that wasted calories.
> In particular, in the evolutionary history of the brain as an energy-optimizing controller of the body, a "System 1" would have been selected against extremely early on, when it directed the internal organs to act according to "heuristics" that wasted calories.
How are the calories are wasted exactly? Our hind brain triggers autonomous reactions to various inputs. Clearly not all such reactions are adaptive, sometimes staying very still and bearing some pain or discomfort is better than death. And so we evolved higher level cognitive faculties to make better choices, just a little slower than the hind brain. This is system 1.
I don't see why the exact same pressures couldn't work at this cognitive level as well. System 1 provided more adaptive reactions to a wider range of situations, but just a little slower than the hind brain. But even still, some metacognitive faculty would yield even better reactions in some circumstances, and so we evolved system 2.
But system 1 still has tremendous significance, because it's much better than our hind brain, is sufficient for most daily scenarios, and is not as calorically expensive as system 2.
The logic behind the efficiency gains is similar to the cache hierarchy in computers. We have more than one cache level because 2-3 cache levels is pretty close to optimal when trading off density, thermal considerations, and efficiency.
>How are the calories are wasted exactly? Our hind brain triggers autonomous reactions to various inputs. Clearly not all such reactions are adaptive, sometimes staying very still and bearing some pain or discomfort is better than death. And so we evolved higher level cognitive faculties to make better choices, just a little slower than the hind brain. This is system 1.
This story is false. The autonomic system isn't autonomous from the rest of the brain: its parameters, "set trajectories", are regulated by the rest of the brain (meaning: the limbic areas of the cortex), while the hypothalamus communicates with the endocrine system to predict and control the body from that angle. As you already say, a truly reactive body-regulator would get you killed very quickly.
Regulating the body by anticipating what it has to do is The Point of a brain. Further, the brain has six intrinsic networks to its functional connectivity, not two modular systems.
There's just no empirical evidence for a dual-process model. There's empirical evidence for an embodied predictive-control model. If you want to arrange this into "layers" from "animalistic" to "human", the way to do it would be to section off the particular cognitive functions which, at times, can be used for offline simulation of the environment, as a mode of metabolic reinvestment of surpluses.