Peeping through my keyhold I see within the range of only about 30 percent of the light that comes from the sun; the rest is infrared and some little ultraviolet, perfectly apparent to many animals, but invisible to me. A nightmare network of ganglia, charged and firing without my knowledge, cuts and splices what I see, editing it for my brain. Donald E. Carr points out that the sense impressions of one-celled animals are not edited for the brian: 'This is philosophically interesting in a rather mournful way, since it means that only the simplest animals perceive the universe as it is.
