Husserl interprets transcendental phenomenology as the true beginning of a science of transcendental subjectivity. This beginning is significantly delayed compared to Kant's first discovery of transcendental subjectivity. According to Husserl, this delay is due to a long period of naturalistic deviation when considering transcendental subjectivity. Starting with British Empiricism and continuing for a long time thereafter in post-Kantianism, this deviation would have led to a functionalist perspective on transcendental idealities. Vaihinger, as the leading German representative of Kantian functionalism at the beginning of the 20th century, should have been one of the primary targets in Husserl's attempt to distinguish his phenomenological proposal from a naturalistically deviant post-Kantianism. But he is not, at least not explicitly. The paper examines the hidden dispute between Husserl and Vaihinger, highlighting its motives and implications based on the ambiguous concept of transcendental "appearance" (as phenomenon and as fiction), as well as both Husserl’s and Vaihinger’s reasons to hide it.