Revelation, or the view that the essence of phenomenal properties is presented to us, is as intuitively attractive as it is controversial. It is notably at the core of defences of anti-physicalism. I propose in this paper a new argument against Revelation. It is usually accepted that low-level sensory phenomenal properties, like phenomenal red, loudness or brightness, stand in relation of similarity and quantity. Furthermore, these similarity and quantitative relations are taken to be internal, that is, to be fixed by (...) what their relata are. I argue that, under some plausible additional premises, no account of what grounds these relations in the essence of their relata is consistent with Revelation, at least if we take common phenomenological descriptions for granted. As a result, the plausibility of Revelation is undermined. One might however resist this conclusion by weakening the epistemic relation postulated between subjects and their phenomenal properties. (shrink)