What it’s like to perceive: Eden vs. The Matrix

07/01/2025

Naïve Realists tell us that a fundamental constituent of a veridical perceptual experience is the mind-independent objects and properties perceived. The view has traditionally been challenged on the grounds that total hallucinations - experiences which don't involve the perception of mind-independent entities - do not seem fundamentally distinct from veridical experiences. In this blog post, Dr Heather Logue argues that the argument from hallucination begs the question against the Naïve realist and that the real source of disagreement can be found in the theoretical starting points that each disputant adopts.

A central concern in philosophy of perception is the phenomenal character of perceptual experience — “what it’s like” to have a perceptual experience of a certain kind. For example, there’s something distinctive it’s like to see red, hear middle C, touch a fuzzy blanket, taste a pickle, smell a rose, and so on.

Contemporary theorising about perceptual phenomenal character is bogged down in an impasse between Naïve Realists, who hold that it consists in the subject perceiving things in their environment, and their opponents, who hold the view that perceptual phenomenal character is entirely in the head. For example, Naïve Realism holds that phenomenal redness (the phenomenal character associated with experiences of redness) consists in perceiving a mind-independent entity (in the good case, a red thing). On this view, perceptual phenomenal character literally has mind-independent entities (like apples) as constituents. By contrast, rival theories hold that phenomenal redness consists in something internal to the subject (e.g., a state of representing something as red, or awareness of a reddish mind-dependent sense-datum).

These days, many philosophers think that Naïve Realism is at best ludicrous, and at worst incoherent. This is because it is currently fashionable to theorise about perceptual phenomenal character by focusing on total hallucinations, like those described in the film The Matrix. In that scenario, the humans’ brains are being stimulated by a complicated machine in order to generate experiences as of living their lives in an ordinary world, when in fact they are lying in vats of goo serving as batteries for their robot overlords. The Matrix is basically a scenario in which nothing about the external mind-independent world is as it seems — what it’s like to have an experience is no guide whatsoever to what the external mind-independent world is like. Naïve Realism certainly isn’t true in the Matrix scenario as it’s typically described: as involving experiences that seem exactly like the kinds of experiences we actually have, but don’t involve perceiving any external mind-independent entities at all. So if we start our theorising about perceptual phenomenal character from the Matrix, Naïve Realism does indeed seem ludicrous.

However, there is another way to theorise about perceptual phenomenal character: one which starts not from the Matrix, but rather from Dave Chalmers’ Eden scenario (2006). In this scenario, subjects have unmediated perceptual contact with the external mind-independent world. Eden is basically a scenario in which we can “read off” the metaphysics of the external mind-independent world from the phenomenal character of perceptual experience—everything about the external mind-independent world is exactly as it seems. Naïve realism seems like the most natural account of perceptual phenomenal character in the Eden scenario; all there need be to phenomenal redness is perceiving an instance of redness.

Of course, we are not in the Eden scenario, and (hopefully) we are not in the Matrix scenario, either. But both scenarios embody different conceptions of what perceptual phenomenal character might be, and serve as different starting points for theorising about it. A Naive Realist can be characterised as taking Eden as their theoretical starting point, and asking: why should we duplicate the world in the brain in order to explain perceptual phenomenal character, when the world is available to do the work? Since the actual world is not Eden, there will be some explanatory work for internal features of the subject (neural and/or representational states) to do. But a Naïve Realist will argue that nothing we’ve learned about the microphysical facts underlying perception, or illusions, or hallucinations, forces us to collapse perceptual phenomenal character entirely within the subject. The Naïve Realist’s primary aim is to minimise our Fall from Eden as much as possible. (Note that this involves questioning whether the Matrix scenario described above is a genuine possibility after all.) By contrast, the Naïve Realist’s opponents can be characterised as taking the Matrix as their theoretical starting point, and asking: why bring the world into it when the brain is explanatorily sufficient? They take it as a fixed point in their theorising that perceptual phenomenal character is entirely internally determined.

Which approach to the metaphysics of perceptual phenomenal character is the correct one? As far as I can see, there’s no way to directly argue for one approach over the other, at least not without begging the question against the other one. The way forward is to be found in Bill Fish’s (2021) suggestion that Naïve Realists and their opponents are engaged in different research programmes — embodied by the Eden-oriented and Matrix-oriented approaches. The main implication of this proposal is that we should let many flowers bloom, and wait and see how the different research programmes fare in their efforts to address the philosophical problems that animate philosophical investigation of perceptual phenomenal character in the first place (e.g., the “hard problem” of consciousness).

In the shorter term, we should avoid getting bogged down in unproductive “cross-programme” first-order disagreements. For example, criticisms of Naïve Realism often depend on presuppositions that emerge from a Matrix-oriented research programme. But if I’m right, such criticisms miss the point — the disagreement is really at a higher level. The disagreement between Naïve Realists and their opponents concerns which claims and aims should serve constraints on our theorising, rather than which theory best satisfies generally agreed-upon constraints.

Dr Heather Logue is an Associate Professor in the School of Philosophy, Religion, and History of Science at the University of Leeds. Her research focuses on issues in philosophy of mind, metaphysics, and epistemology. She currently has a British Academy Mid-Career Fellowship to finish her book World in Mind, which elaborates on the ideas in this blog post.