How should we explain ‘what it is like’ to perceive colour? One of the reasons why naïve realist theories of colour are interesting is that they promise to contribute towards a solution to the problem of consciousness.
There is something puzzling about the way that problems about consciousness and conscious experience are normally presented. Take Jackson’s Knowledge Argument as an example. In Jackson’s example, Mary is a scientist who knows all the physical facts about colour and colour perception, but she has never herself seen a chromatically coloured object – she has spent all her life in a black and white room. When she sees, say, a red apple for the first time, Jackson argues that she will learn something new, namely ‘what it is like’ to perceive colour. He concludes that there are facts that are not physical facts.
There is a lot that has and can be said about the Knowledge Argument, but here I want to focus on the question of what is the Knowledge Argument an argument for? It is widely assumed – both by those who accept the Knowledge Argument and those who don’t – that if Mary learns something when she sees a red apple for the first time, then she learns something about herself. Specifically, the argument is standardly taken to be an argument for the existence of qualia: intrinsic, qualitiative properties of experience.
But why, when Mary first sees an object of a certain kind, such as a red apple, should she be thought to learn something about herself? Why doesn’t she learn something about the object that she sees—namely, what redness, a property of the object, is like? (Or at any rate, if she does learn something about herself, why isn’t what she learns about herself parasitic on what she learns about the object?)
Here is one explanation of why the Knowledge Argument is normally assumed to be an argument for the existence of qualia, not colours: it is assumed in advance that there are no properties of physical objects that could explain ‘what it is like’ to perceive colour. And although there are different reasons for believing this, a common reason is that physics ‘tells us’ that colours as we perceive them do not exist. (This, at any rate, is something that Jackson himself argued for in earlier work defending a sense-datum theory of perception.) Assuming that Mary cannot learn anything new about physical objects when she first sees a red apple, then she must—if she learns anything—learn something about herself.
If this diagnosis is correct, then a central argument against physicalism itself relies on physicalist assumptions. This is not strictly inconsistent: it is possible to think that physics fully describes material objects but not conscious subjects. But there is at least a tension here. If science ‘tells us’ that there are no colours, then why doesn’t it ‘tell us’ that there are no qualia, either? After all, qualia play no role in scientific explanations. And if qualia can play no role in scientific explanations and still exist, then why should it follow from the fact that scientists do not appeal to colours to explain colour experiences that colours do not exist?
It is not just that there are arguments for the existence of colours that parallel standard arguments in the philosophy of mind for mind-brain distinctness—such as the Knowledge Argument, but also Kripke’s Modal Argument, the explanatory gap, and the hard problem of consciousness. Once these problem are internalised, and made into problems about conscious subjects, they can come to seem increasingly intractable. As it is normally understood, the Knowledge Argument is supposed to establish the existence of intrinsic qualitative properties of experience. But if we reflect on our experience, we seemingly aren’t aware of any properties of this kind. Experience is ‘transparent’: we ‘see through’ the experience to the objects in the mind-independent world that the experience is an experience of. So it is not just that there is no scientific evidence for the existence of qualia; there is seemingly no introspective evidence, either.
The naïve realist theory of colour provides an alternative way approaching problems associated with consciousness and conscious experience. According to the naïve realist, colours are mind-independent properties of objects that are distinct from their physical properties. The naïve realist therefore rejects one of the assumptions that is liable to make consciousness seem particularly problematic: that colours as we perceive them do not exist. If the naïve realist theory of colour is, in turn, combined with a naïve realist theory of perception, according to which ‘what it is like’ to have an experience is determined by the mind-independent objects and properties that we are related to in perception, then this provides an explanation of the qualitative character of colour experience. ‘What it is like’ to perceive colour is explained by the nature of the colours that we perceive.