There is an idea in the air, in the background, hovering about, that the functioning of our brains is far from optimal. No doubt our thinking is not perfect but not in the way that many people imply.

Take vision as an example. The argument goes: vision is about forming an accurate picture of what is in front of our eyes, therefore any deviation from that accuracy is an imperfection that contaminates our sight. So illusions get treated as a weakness of the system. Then we notice that the illusions help us with consistency, depth perception, prediction and so on. Illusions are not weaknesses at all but very useful aspects of vision that are only noticeable in ambiguous and artificial situations.

Or take language as an example. The argument goes: language is about forming logical statements about reality, therefore any deviation from the logic of a language’s grammar is a weakness in our use of language. But we really know that language is not about logic but about communication. And we know that language is only a part of communication. When people speak they are not striving for good logic but for good communication. The problems with logic become visible when language is written down and then examined minutely and out of context.

Or take decision making. The argument goes: good decisions are rational decisions, emotion interferes with rationality and therefore emotion should be eliminated from decision making. However, emotion is how we establish a value system. We cannot make good decisions if the only value system we accept is a monetary (or similar) one.

Here is the way we should look at our weaknesses. We have to take time into consideration. We do not have the time to form an accurate image of the world before the whistle blows and we have to act in that world. We need some ‘quick and dirty’ tricks along side more detailed analysis to get us through life. When we speak we do not always have time to communicate in well formed logically pristine sentences. We do the best with the time available – the best at communication not at logic. Nor do we have the time to make complicated spreadsheet type analysis for our decisions. A decision that is too late can be as bad as a weak decision, sometimes worse.

Here is another way is see the problem. No doubt in elementary school you were taught to roughly estimate the answer to a mathematical problem before doing all the long hand arithmetic. Advice that is mostly ignored. I was also taught to use a slide rule first before having to use other methods for more significant figures. I was told to do calculations on a calculator with well rounded numbers and accurate numbers of zeros first and then do the calculation with the full numbers. Three different teachers at three stages of my life giving me the same message, “take a little time and protect yourself from huge, gross errors but comparing your answer to a rough estimate.” It seems our brains do both quick estimates and slow calculations and they are checks on one another.

Finally many people seems to dislike the wet, wiggling, squashiness of living things. Accuracy is not an end in itself, life is. Logic is not an end in itself, life is. We may see other goals but our biology has its own. We should not consider our brains as faulty unless they are failing in a biological sense.