Abstract
Higher-order theories of consciousness come in many varieties, but all adopt the 'transitivity principle' as a central, explanatory premise. The transitivity principle states that a mental state of a subject is conscious if and only if the subject is aware of it. This higher-order awareness is realized in different ways in different forms of higher-order theory. I argue that empirical studies of metacognition have falsified the transitivity principle by showing that there can be awareness of a mental state without that state's becoming conscious. I present two such studies in detail and argue that the measures they employ cannot be interpreted in a way that would make the results compatible with higher-order theory. Since all versions of the theory rely on the transitivity principle, this entails that all forms of higher-order theory are false.