Excluding the idea of its continuation in deep sleep, consciousness is either on or off. We say that someone has 'come to' when they awaken out of unconsciousness - this can either be intended to mean 'come to consciousness', as if it is the self for whom consciousness is either on or off - the self, enduring and unchanging and not in essence conscious - or it could mean 'come to presence' as a synonym for consciousness. But like a screen being activated this says nothing about what appears, or is to appear, on it, or in it. (Do phenomena appear before or in consciousness? Do they appear 'on' something?) There are many kinds and textures of consciousness and each of them is multi-layered. We are aware of the quality of consciousness at the same time as we are absorbed in the content of it, and if there is a change in the relationship of these that is outside our expectation then we are instantly alert to it, it is felt in a kind of kinaesthesia. This already requires three layers, which could be called content, context and the relationship of content and context. The layers are not rigidly separated but flow into and contaminate each other. As soon as something is objectified, or held in the focus of attention it becomes a part of content, as soon as it ceases to be focal it becomes part of context. The textural differences of consciousness have many dimensions, at least as rich as the various kinds of music: scope, clarity, permeability and others. Among these there is one which is something like frequency or wavelength, orthogonal to the others, and which seems to refer back to attributes, although they are not attributes, of the self more than of the mind.