How did Husserl distinguish knowledge of facts from knowledge of essences?

Edmund Husserl distinguished between knowledge of facts and knowledge of essences by utilizing the phenomenological reduction, which requires setting aside, or "bracketing," the factual existence of the world to focus on the structures of consciousness.1

While history and empirical sciences are concerned with contingent facts, phenomenology seeks a rigorous, scientific knowledge of essences—the invariable, necessary structures of things. Husserl achieved this through the eidetic reduction, a method that moves beyond individual, concrete objects to the "eidos" or pure essence.23

The process involves:
* Free Variation: Starting with a concrete factual object, the philosopher imaginatively varies its aspects.
* Intuition of Essences (Wesensschau): By focusing on what remains unchanged throughout these variations, the philosopher identifies the "invariant"—the essential structure that defines the object.21

Unlike empirical generalization, this method does not rely on induction; it abstains from positing the actual existence of objects, instead moving from the perceptual sphere to the imaginative sphere to grasp the universal and unchangeable nature of phenomena.21