Abstract
Our article seeks to demonstrate that Husserl’s approach to intersubjectivity
in his First Investigation of 1901/1913 was rigorous rather than rash. To do so, it applies a combination of intentionality and whole-part logic that has been overlooked
in Husserl study. It therefore starts from Husserl’s Prolegomena of 1901 to follow his
normative phenomenology until it excludes knowledge of another’s consciousness,
then unpacks how he does so by his “proofs” in his 1913 Third Investigation (also
considering his 1901 version), to apply those results to his First Investigation. The
outcomes might demonstrate an unexpected rigour in Husserl’s early address to inter-
subjectivity, and even support a novel logic that considers alterity.