Proposes that black holes carry entropy proportional to horizon area (in Planck units), based on the analogy between the area theorem and the second law of thermodynamics. This entropy proposal, combined with area non-decrease, is what pushed Hawking to look for — and find — the compensating thermal emission (1974/1975) needed to make black-hole thermodynamics fully consistent; it is the conceptual seed of Hawking radiation. relevance_note: conceptual precursor establishing black-hole thermodynamics, the framework within which Hawking radiation (Premise A) was derived.