This book shows, for the first time in its full spectrum, the interconnectedness and topicality of two historically and philosophically significant developments of philosophical theories of the study of mind: that of phenomenology of Edmund Husserl and phaneroscopy of Charles S. Peirce. The chapters in this book put the two thinkers in a novel discourse while engaging in mutual scholarship on the large overlaps between the historically two largely independently developed but converging ideas of mind, cognition, consciousness, being, and experience. It is the second volume in a projected series of three, the first of which is Peirce and Husserl: Mutual Insights on Logic, Mathematics, and Cognition (2019). This book consists of three parts. Part I contains studies on the basic elements and the methodological themes of both “phenomenologies” vis-à-vis each other. Part II of the book is dedicated to metaphysical and existential themes. Finally, this book contains a hitherto unpublished selection of connected texts from Charles Peirce concerning phaneroscopy, the theory of definitions, and other related historical, philosophical, and religious themes from 1910, transcribed and introduced by one of the editors of the volume. This book is of interest to scholars in phenomenology, phaneroscopy, and the history of ideas.