This book introduces a new category, in-between, that will have a far-reaching impact on classic ways of thinking. Husserl's description of consciousness and Whitehead's criticism of the prejudice of simple location are two starting points. Relativity theory's radical changes in the conception of space and time also motivate some of the lines of thought. The initial two chapters are devoted to preparatory analysis. The first presents an argument against visual reasoning; the second compares the role of relations to the role of terms. The balance of the volume discusses in-between in general, then its role in linguistics, history, ethics, and aesthetics, and finally in intersubjectivity and the faculties of the mind. Co-published with the Center for Advanced Research in Phenomenology.