Animals, consciousness, and I-thoughts

Abstract

This chapter discusses and elaborates upon the evidence for higher-order thoughts (or I-thoughts) in animals. It also shows that the higher-order thought (HOT) theory is indeed consistent with animal consciousness. The chapter argues that recent experimental evidence on animal memory and metacognition strongly suggests that many animals have the self-concepts and mental-state concepts necessary to form I-thoughts. It answers to the claim that having I-thoughts requires having thoughts (and thus concepts) directed at others' mental states. The stakes are high because if the HOT theory is true, any evidence indicating the absence of I-thoughts would also cast doubt on animal consciousness itself. The very concept of "consciousness" is notoriously ambiguous, but perhaps the most commonly used contemporary notion of a "conscious" mental state is captured by Thomas Nagel's famous "what it is like" sense.