Husserl himself considered Logical Investigations (1900-1901) to constitute his `breakthrough' to phenomenology, and it stands out not only as one of Husserl's most important works, but as a key text in twentieth century philosophy.

I. Problems of Logic.- Different Concepts of Logic and Their Relation to Subjectivity.- The Logical Investigations: Paving the Way to a Transcendental Logic.- Non-Objectifying Acts.- What is “Logical” in Husserl’s Logical Investigations? The Copenhagen Interpretation.- II. Realism and Idealism.- The World Well Won: Husserl’s Epistemic Realism One Hundred Years Later.- “Aristotelian” Themes in Husserl’s Logical Investigations.- Metaphysical Neutrality in Logical Investigations.- III. Categorial Intuition.- Husserl’s Revision of the Sixth Logical Investigation.- Husserl’s Concept of Categorial Intuition.- Categories, Diagrams, Schemata: The Cognitive Grasping of Ideal Objects in Husserl and Peirce.- IV. Semiotics, Alterity, Cognitive Science.- Semiotics in Husserl’s Logical Investigations.- The Puzzling Case of Alterity in Husserl’s Logical Investigations.- The Relation of Husserl’s Logical Investigations to Descriptive Psychology and Cognitive Science.- Dorion Cairns: The First Motivation of Transcendental Epoché.