I’ve discussed many times how difficult consciousness can be to define. One of the earliest modern definitions, from John Locke, was, “the perception of what passes in a man’s own mind.” This definition makes consciousness inherently about introspection. But other definitions over the centuries have focused on knowledge in general as well as intentionality, the ability of thoughts to be about something. Philosophers in the 20th century started focusing on the phenomenal nature of consciousness, the “what it’s like” aspects.
One way I’ve responded to this range of definitions has been with a hierarchy. But this has generally been functional in nature and discussed from the perspective of outside the system. It’s a useful response when considering evidence cited for various animal species being conscious, as well as various liberal conceptions of consciousness like panpsychism. It allows us to discuss what particular systems might have, but also what they’re missing.
But it’s also subject to criticism like the kind Mark Solms gives against modern cognitive science, that it removes the first person “I” from its deliberations. I think this happens because including this perspective often clouds the issue, and assertions about it are difficult to establish objectively. Still, it’s a perspective many people interested in consciousness feel is neglected by science.
Which makes me think of a different type of hierarchy, one built with the inside perspective. It starts with Locke’s definition, the introspective one. I think this makes sense because everything we know about our own consciousness comes from introspection. Without introspection, we wouldn’t even have a concept of our own consciousness. This will make this hierarchy very human specific, but hopefully we’ll see room for other species in it.
This new hierarchy, as I’m currently conceiving of it, has four layers.
- Introspective perception.
- The perceived.
- The perceivable.
- The unperceivable.
The first one, introspective perception, are the impressions we have of what is happening in our mind. For centuries, philosophers conceived that this was the whole show, that the mind was transparent to itself and its knowledge of itself was infallible. Modern psychology hasn’t left much room for this view. It’s pretty well demonstrated that introspection, while effective for day to day feedback on our own thoughts, isn’t a reliable source of information about the mind.
The second, the perceived, is the source of the introspective perception. This seems largely correlated with the contents of top down attention. So another way to refer to this might be “the attended.” However, attention is a multilevel phenomenon and there are aspects of it which can be dissociated from conscious awareness, so I thought it best to avoid implying they were the same.
The third, the perceivable, is anything about our own mind that might be perceivable. At any one time, most of what goes on in our brain that is perceivable is not being perceived. Again, this could be thought of as what is currently outside of attention, although it might be something we’re attending to and still not be perceived, such as being in automatic mode while driving home while thinking about that TV show you’re going to watch tonight.
The final one, the unperceivable, is anything that happens in our brain that we never have access to, such as regulation of heart rate, hormone levels, and other autonomic functions. We can often perceive the effects of these processes, and may be able to affect them indirectly, but they’re inaccessible to introspection.
The question is, where in this hierarchy is consciousness? Which answer you feel is correct may influence which scientific theories of consciousness you find more plausible. Someone who answers 3, the perceivable, may focus on local theories such as local recurrent processing. Advocates of these theories usually see consciousness, particularly phenomenal consciousness, as something that can “overflow” our ability to self report.
If you favor 2, the perceived, then you’re probably going to focus on access-consciousness theories such as the various global workspace ones. These theories tend to see 3 not as conscious, but preconscious content, content that has the potential to become conscious but won’t necessarily make it.
And if you require 1, then you’re most likely to see metacognitive theories, such as higher order thought theories, or Michael Graziano’s attention schema theory, as more plausible. These theories vary somewhat in how distinct they see 1 and 2, with some higher order theories insisting that the entire conscious experience is in 1. While many global workspace theories tend to see 1 as an add-on, an enhancement.
It’s worth noting that seeing consciousness in 2 or 3 leaves a lot more room for non-human animal consciousness. Although many advocates of higher order theories discuss various level of metacognition, including explicit and implicit varieties, that may still allow many species in club consciousness.
What is the correct view? I’m tempted to say there’s no fact of the matter here since all of these layers are real. But there are some distinct scientific questions between layer 1 and 2, in how much of, say, the experience of seeing a red apple resides in each layer. We might know the answer to this in the next few years. But I’m not sure the same distinction exists for layers 2 and 3. Here the difference might well be completely philosophical, that is, definitional.
What do you think of this new hierarchy? Am I missing anything?