Does consciousness matter?

Chapter 7 concluded that there is no fact of the matter concerning phenomenal consciousness in animals, while also arguing that this conclusion is of no importance for science. The present chapter inquires whether it is nevertheless important in other ways, specifically for our ethical treatment of animals, arguing that it is not. But a challenge remains for those who theorize about the moral status of animals: they need to prize the foundations of their theories apart from assumptions about consciousness. The chapter also considers what should be said about the phenomenally conscious status of humans who, like animals, only partially share a full global-broadcasting architecture, such as human infants and people suffering from age-related cognitive impairments.

Consciousness in animals

This chapter argues that if a global workspace theory of phenomenal consciousness is correct, and is fully reductive in nature, then we should stop asking questions about consciousness in nonhuman animals. But this is not because those questions are too hard to answer, but because there are no substantive facts to discover. The argument in support of this conclusion turns on the idea that while global broadcasting is all-or-nothing in the human mind, it is framed in terms that imply gradations across species. Yet our concept of phenomenal consciousness doesn’t permit mental states to be to some degree conscious. Moreover, the first-person concepts that give rise to the problem of consciousness cannot intelligibly be projected into minds significantly different from our own.

Explaining the “hard” problem

This chapter shows that global-workspace theory can be developed into a satisfying, fully reductive explanation of phenomenal consciousness. It shows how globally broadcast nonconceptual content enables higher-order thoughts about that content, where those thoughts can lack conceptual connections with physical, functional, or representational facts. As a result, zombies are conceivable and an (epistemic) explanatory gap is opened up. But the thoughts in question can themselves be given a fully naturalistic explanation. Hence all of the facts involved in consciousness can be fully explained. The chapter defends the reality of the phenomenal concepts needed to make this account work, and replies to a dilemma for the account proposed by David Chalmers.

Global-workspace theory

The present chapter outlines and defends the empirical case supporting global-workspace theory as the best account of the functional/neural correlates of consciousness, at least. The chapter explains the theoretical background to global-workspace theory and the evidence that supports it. It shows how the theory is well-supported by raft of findings in psychology and cognitive neuroscience, as well as by recent experiments tracking conscious contents in the brain. The chapter also replies to a variety of critiques and alleged forms of counter-evidence. It concludes by considering whether the fact that much of this evidence has been collected in work with nonhuman animals begs the consciousness-question that forms our topic (arguing that it does not).

Animal minds

If animals lack mental states altogether then of course they can’t be capable of phenomenal consciousness, either. And even assuming that they have mental states, it would be natural to think that much might turn on just how sophisticated the minds of various species of animal are, and on the extent of the discontinuities between human and animal minds. The present chapter argues against strong discontinuity views. It also considers evidence of working memory, planning, self-control, metacognition, and language in animals, which are especially relevant to later discussions. I argue that there is significant and widespread support for the first three, but little evidence supporting metacognition or language.

The need for a theory

The present chapter argues that the problem of animal consciousness can’t be tackled directly, without commitment to any particular theory of consciousness. In the course of doing so, it discusses evidence of the existence of unconscious perceptual states, as well as one recent effort to put the emergence of consciousness into phylogenetic context. Finally, it outlines the constraints that a successful theory of consciousness should meet.

Important preliminaries

This chapter does some initial—but important—ground-clearing and foundation-building. It starts by drawing a number of distinctions, more precisely delineating the target, and setting the terms for the debates that follow. It explains some of the different things that people mean by “consciousness,” in particular, as well as some of the claims that have been made about the nature of consciousness. The chapter also argues in support of a pair of substantive theses on the topic that will be relied upon later. Specifically, it argues that phenomenal consciousness is exclusively nonconceptual in nature, and that it doesn’t admit of degrees: it is either categorically present or categorically absent. Finally, the chapter situates the topic in relation to the traditional problem of other minds.

Some initial possibilities

The present chapter surveys and critiques the leading competitors lined up against the global-workspace theory of consciousness, which will be presented and defended in Chapter 5. These are: integrated-information theory; a theory that identifies phenomenal consciousness with information represented in the upper brain-stem; a theory that identifies it with the contents of a fragile form of short-term memory, distinct from working memory; higher-order thought theory; and dual-content theory, which is also higher-order in character. The implications of these theories for the distribution of consciousness across the animal kingdom are also considered.