Qualia
First published Wed Aug 20, 1997; substantive revision Mon Apr 22, 2013
Feelings and experiences vary widely. For example, I run my fingers over sandpaper, smell a skunk, feel a sharp pain in my finger, seem to see bright purple, become extremely angry. In each of these cases, I am the subject of a mental state with a very distinctive subjective character. There is something it is
like for me to undergo each state, some phenomenology that it has. Philosophers often use the term ‘qualia’ (singular ‘quale’) to refer to the introspectively accessible, phenomenal aspects of our mental lives. In this broad sense of the term, it is difficult to deny that there are qualia. Disagreement typically centers on which mental states have qualia, whether qualia are intrinsic qualities of their bearers, and how qualia relate to the physical world both inside and outside the head. The status of qualia is hotly debated in philosophy largely because it is central to a proper understanding of the nature of consciousness. Qualia are at the very heart of the mind-body problem.
The entry that follows is divided into ten sections. The first distinguishes various uses of the term ‘qualia’. The second addresses the question of which mental states have qualia. The third section brings out some of the main arguments for the view that qualia are irreducible and non-physical. The remaining sections focus on functionalism and qualia, the explanatory gap, qualia and introspection, representational theories of qualia, qualia as intrinsic, nonrepresentational properties, relational theories of qualia and finally the issue of qualia and simple minds.
1. Uses of the Term ‘Qualia’
(1) Qualia as phenomenal character. Consider your visual experience as you stare at a bright turquoise color patch in a paint store. There is something it is like for you subjectively to undergo that experience. What it is like to undergo the experience is very different from what it is like for you to experience a dull brown color patch. This difference is a difference in what is often called ‘phenomenal character’. The phenomenal character of an experience is what it is like subjectively to undergo the experience. If you are told to focus your attention upon the phenomenal character of your experience, you will find that in doing so you are aware of certain qualities. These qualities — ones that are accessible to you when you introspect and that together make up the phenomenal character of the experience are sometimes called ‘qualia’.
There are more restricted uses of the term ‘qualia’, however.
(2) Qualia as properties of sense data. Consider a painting of a dalmatian. Viewers of the painting can apprehend not only its content (i.e., its representing a dalmatian) but also the colors, shapes, and spatial relations obtaining among the blobs of paint on the canvas. It has sometimes been supposed that being aware or conscious of a visual experience is like viewing an inner, non-physical picture or sense-datum. So, for example, on this conception, if I see a dalmatian, I am subject to a mental picture-like representation of a dalmatian (a sense-datum), introspection of which reveals to me both its content and its intrinsic, non-representational features (counterparts to the visual features of the blobs of paint on the canvas). These intrinsic, non-representational features have been taken by advocates of the sense-datum theory to be the sole determinants of what it is like for me to have the experience. In a second, more restricted sense of the term ‘qualia’, then, qualia are intrinsic, consciously accessible, non-representational features of sense-data and other non-physical phenomenal objects that are responsible for their phenomenal character. Historically, this is how the term ‘qualia’ was first used in philosophy. It was introduced in 1929 by C.I. Lewis in a discussion of the sense-datum theory. As Lewis used the term, qualia were properties of sense-data themselves.
(3) Qualia as intrinsic non-representational properties. There is another established sense of the term ‘qualia’, which is similar to the one just given but which does not demand of qualia advocates that they endorse the sense-datum theory. However sensory experiences are ultimately analyzed — whether, for example, they are taken to involve relations to sensory objects or they are identified with neural events or they are held to be physically irreducible events — many philosophers suppose that they have intrinsic, consciously accessible features that are non-representational and that are solely responsible for their phenomenal character. These features, whatever their ultimate nature, physical or non-physical, are often dubbed ‘qualia’.
In the case of visual experiences, for example, it is frequently supposed that there is a range of visual qualia, where these are taken to be intrinsic features of visual experiences that (a) are accessible to introspection, (b) can vary without any variation in the representational contents of the experiences, (c) are mental counterparts to some directly visible properties of objects (e.g., color), and (d) are the sole determinants of the phenomenal character of the experiences. This usage of ‘qualia’ has become perhaps the most common one in recent years. Philosophers who hold or have held that there are qualia, in this sense of the term, include, for example, Nagel (1974), Peacocke (1983) and Block (1990).
(4) Qualia as intrinsic, nonphysical, ineffable properties. Some philosophers (e.g, Dennett 1987, 1991) use the term ‘qualia’ in a still more restricted way so that qualia are intrinsic properties of experiences that are also ineffable, nonphysical, and ‘given’ to their subjects incorrigibly (without the possibility of error). Philosophers who deny that there are qualia sometimes have in mind qualia as the term is used in this more restricted sense (or a similar one). It is also worth mentioning that sometimes the term ‘qualia’ is restricted to sensory experiences by definition, while on other occasions it is allowed that if thoughts and other such cognitive states have phenomenal character, then they also have qualia. Thus, announcements by philosophers who declare themselves opposed to qualia need to be treated with some caution. One can agree that there are no qualia in the last three senses I have explained, while still endorsing qualia in the standard first sense.
In the rest of this entry, we use the term ‘qualia’ in the very broad way I did at the beginning of the entry. So, we take it for granted that there are qualia. Later on, in section 8, we discuss specifically the view of qualia as intrinsic, nonrepresentational properties. . . .
