What ecological advantages do animals gain by being able to detect, extract and exploit wavelength information? What are the advantages of representing that information as hue qualities? The benefits of adding chromatic to achromatic vision, marginal in object detection, become apparent in object recognition and receiving biological signals. It is argued that this improved performance is a direct consequence of the fact that many animals' visual systems reduce wavelength information to combinations of four basic hues. This engenders a simple categorical (...) scheme that permits a rich amount of sensory information to be rapidly and efficiently employed by cognitive machinery of limited capacity. (shrink)

The 65th year of a scholar who has devoted 40 years to editing and elucidating Robert Grosseteste provides us with a collection of essays. Not surprisingly, they emanate from colleagues and former students of Richard Dales and reflect his interest, among other concerns, in Grosseteste's aspectus et affectus - range of vision and disposition of mind - those twin peaks with which the 13th century thinker helped to get Christian thought through Aristotle without mutual destruction.