Most people think of memory as the ‘past’ and judge it by how well it preserves the past. But that is not its function. Memory is material to be used in the ‘present’ and the ‘future’. What happened in the past is not important except to help understand the present and predict/plan the future. Bits of memory out of historical context are the ingredients of imagination. With more context they are the tools we use to identify things in the present and understand their dangers and opportunities. We need to know if we are encountering the old or the new. We need to remember whether someone is trustworthy when we deal with them. When we look at what we remember, how and how long we remember it, and how closely we keep it to the original memory, we should think of what is the point of all of it.
What seems a fault with memory – that memories are not fixed but can change or be lost altogether – is only a side effect of their being modified to stay relevant and useful. We need memories that help us perceive the present and model the future and that is the real criteria, not absolute accuracy. The criteria for a well constructed memory system are biological evolutionary survival ones.
Colour vision is not about accurately perceiving the frequencies of light coming into the eye. It is not about the light; it is about the surface that reflected the light and how it can be identified. There is no use in saying that our vision is not giving us accurate colour, because accurate colour would interfere with accurate characterization of surfaces and identification of objects. The many optical illusions are not faults in the system – they are due to the ways that the visual system protects the stability of our vision so that things do not appear to change colour or size.
Language is not about meaning or logic; it is about communication. People worry about changes in the meaning of words and the use of grammatical forms. Well, here is what happens generation after generation: if people have difficulty communicating, they will change their language. If their way of life changes, if they move to a different region, if the people they are talking to change, then they will change their language. Our language is not the result of biological evolution so much as cultural evolution. But the same idea applies and the criteria have to do with communication. Is language logical? It may seem so from within that language but talk to anyone learning it as a new language and see the illogical, arbitrary quirks in it. There are languages that count negatives and there must be an odd number to be negative. There are languages that have to have all or no words carry a negative marking. Both types of negation seem logical to the speakers. Is language a good communication tool? Without doubt it is better than anything else we have ever tried to invent. No artificial language has ever made a dent on a natural language no matter how clear was the meaning or logical the grammar of the new language.
When we look at biological and even social systems it is important to consider what is their real, primary reason for existence. We have a tendency to misjudge the criteria and need to watch out for this trap.