Many people find consciousness deeply puzzling. It is often described as one of the few remaining problems for science to address that is genuinely deep—perhaps even unsolvable.
Indeed, consciousness is thought to present a challenge to the prevailing scientific image of the universe as physical through-and-through. In part this puzzlement arises because people are (at least tacitly, on an unconscious level) innate dualists—they consider there to be a division between the mental and physical, the mind and body—resulting from a deep disconnect between the core principles of our intuitive, common-sense, or so-called “folk” psychology and the structure of our intuitive (pre-scientific) physics.
This is why people the world over have always been open to belief in ghosts and spirits, as well as the possibility of an afterlife. It is hard for them to see how the mind could be comprised of arrangements and interactions of physical matter. But this problem—the problem of how mental states in general can be physical—has arguably been solved by cognitive science through some combination of functionalism and the representational theory of mind. That is, the mind is comprised of physical states that perform distinctive functional roles—such as motivating actions in the case of desires, or guiding them in the case of beliefs—while carrying information about (and representing) objects and properties in the world outside of the thinker.
Even cognitive scientists continue to find consciousness mysterious, however. But this is not the consciousness of being awake versus asleep, nor the sort of consciousness involved in being conscious of (that is, perceiving) some event in one’s environment. Neither of these is mysterious from the standpoint of cognitive science. What is thought to be puzzling is so-called phenomenal consciousness—the introspectively accessible felt properties of our experiences. The nature of this puzzlement is best captured through—and arguably depends on—philosophers’ thought experiments. (My view is that cognitive scientists wouldn’t take these thought experiments seriously were it not for their own tacit dualism about the mind; and non-scientists find the consciousness-debate so fascinating because it confirms their tacit dualism about the mind.) For it seems that I can imagine a creature for whom perceiving the greenness of grass feels introspectively to it in just the same way that seeing the redness of a rose feels to me. Indeed, it seems that I can imagine a creature exactly like myself in all respects (physical, functional, and representational) except that it lacks this (the way my current experience of red feels to me). Many think, in consequence, that phenomenal consciousness involves special properties—often called “qualia”—that aren’t explicable in physical terms.
In fact, however, there are no special properties. There are no qualia. The temptation to think otherwise derives from the special way in which we can think introspectively about our own perceptual states, deploying concepts such as this (feel of my experience of red). The “problem” of consciousness merely arises out of the contrast between first- and third-person modes of thinking about our own states. For it is one-and-the-same state, with one-and-the-same set of physical and functional properties, that can be thought of now as a perception of red and now as this feel. The latter is just a different way of thinking of the very same state as the former.
Given that there is no extra property that enters the world with phenomenal consciousness, it follows that the question of consciousness in non-human animals is of no scientific importance. There are many important questions that arise when comparing the minds of ourselves and other animals. We can ask about capacities for long-term planning in animals, for example, and we can ask to what extent their working-memory capacities resemble our own. But the question of qualia isn’t among those questions. For there are no qualia. There are just perceptual states that are available to be thought about (in humans) using a distinctive set of first-person concepts like this feel.
Some will say that although the question of animal consciousness might not matter for science, it surely matters for ethics. And indeed, as the continuities between human and animal minds have been increasingly recognized, so people have come to feel that it is urgent to identify the set of creatures that are capable of consciousness. This may be because consciousness is a prerequisite for empathy. One can’t enter imaginatively into the experience of another creature unless those experiences, like one’s own, are like something to undergo, it is thought. But empathy arguably is not, and shouldn’t be, foundational to ethical thinking. And the emotion of sympathy, in contrast, can be grounded in a third-person understanding of the desires and sufferings of the creature in question. Perhaps this may be all that is necessary for questions about the ethical treatment of animals to arise.