Why do we have sense-organs? We have ears, intricate structures composed of membranes, bones, channels, etc., a nose with two nostrils and a mucous membrane which covers a nasal cavity. We have taste buds, a range of tactile sensors under our skin, not to mention the eyes. Why?

The simple answer is that we have sense-organs because they enable us to perceive. A sense-organ, as Aristotle would say, is an organon, a tool or instrument of perception. But to understand why the sense-organ is instrumental in perception we must understand something about perception. Just as we must understand something about gardening before we can appreciate the usefulness of a rake, so we must understand something about sense-perception before we can see the point of having a sense-organ. An explanation of the sense-organs must therefore start with an understanding of what sense-perception is. Once we understand what sense-perception is, we can explain how the sense-organs help bring about sense-perception as we have understood it.

In modern science it can be taken for granted that the explanation of perception will refer to physical processes. For example, vision is said to be the process whereby the eyes ‘feed the brain with information coded into neural activity — chains of electrical impulses — which by their code and the patterns of brain activity, represent objects’.