Both Heidegger and Husserl traced their starting points to the same teacher, Brentano

Evidence

Oddly, Heidegger was first inspired to set off down this route by reading Franz Brentano — not Brentano’s paragraph on intentionality, but his doctoral thesis, which concerned different meanings of the word ‘being’ in the works of Aristotle. The philosopher who led Heidegger to notice being was the same who led Husserl to intentionality, and thus to the inward turn. — Sarah Bakewell, At the Existentialist Café, 175

Categorization

• XREF: A single intellectual root (Brentano) branching into two opposed traditions — a neat parallel to other cases where one common ancestor yields divergent schools. — connects to: Brentano’s Vienna teaching style shaped Husserl’s philosophical direction. — Sarah Bakewell, At the Existentialist Café: Freedom,…, 129; Husserl founded phenomenology after Brentano converted him from mathematics to philosophy — Sarah Bakewell, At the Existentialist Café: Freedom,…, 128; Brentano’s Aristotle thesis diverted Heidegger toward Being while other Brentano work turned Husserl inward — Sarah Bakewell, At the Existentialist Café: Freedom,…, 175
• FICTION: Fertile seed for narrative: two estranged movements discovering they share one hidden originator — a premise for a story about buried intellectual kinship.