Mind is an inner property of individual being but, paradoxically, to live in the social world requires being able to know what is in other people’s minds. This article explores two approaches to making sense of this paradox; the concept of “theory of mind” and the phenomenological concept of “intersubjectivity.” Theory of mind is discussed in terms of its development as a concept in cognitive psychology to understand autism and intersubjectivity is discussed in relation to five processes—co-presence, apperception, empathy, the look, and communicative interaction—that are described in the work of phenomenologists including Husserl, Merleau-Ponty, Sartre, and Schutz. The paper argues that while “theory of mind” has stimulated research and discussion on autism, the phenomenological understanding of “intersubjectivity” is more appropriate to trying to understand the difficulties faced by people with autism.