Nick Humphrey, of King’s College, Cambridge, in a recent broadcast on Human Evolution, made the following comments (slightly paraphrased from my notes of the radio broadcast): ‘Man, in comparison to the chimp is a forgetful ape. Chimps in experiments have a remarkable visual memory, recalling for example 25 complex patterns. Some humans can do the same, but rarely, and often where there is a brain malfunction as with epilepsy or damage to the parietal lobes. In effect it is characteristically pathological. Why was this facility suppressed? In order to replace this means of storing knowledge with a new way of thought. Not one of counting objects or observations as particular, but instead ordering such data into general models of things and situations, as with the Platonic Ideal forms. This was the birth of symbolic thought.’