In the latest edition of Philosophy Now there is the usual invitation to readers to send the answer to a question in no more than 400 words. This time it is: ‘What Are The Limits of Knowledge?’.

‘Knowledge’ implies something solid and dependable - actual data we have about our world: an event or how something works – seeing how a machine works through the turning of its cogs. But... It is obvious that whilst there can be a true, all-embracing, description of an event, what is in fact reported as having happened by each person present at that event will differ. Each would say it was what they saw and heard but it is actually what they remember of what they witnessed, something which is partial and changes with time.

Of course a truly comprehensive description would also demand a vast amount of data, which means that we limit ourselves to accepting what we perceive to be the important points as a description of the event itself.

And these days, we are less likely to be able to see the cogs whirring. In future, we shall have to rely on information supplied by the algorithms powering AI, without any of its workings being visible to us. So then, not knowledge in a direct sense, but a computer’s representation of the facts.

So then our knowledge looks to be set on a rather shaky foundation, rather than being the solid body of facts we would like it to be.  It is inherently limited. It is further limited because the knowledge which I can store is limited and will all disappear when I drop off my twig. Before then, my memory will become increasingly unreliable. I can of course store my knowledge of things in some external memory. Diarists have always done just that. And, in principle, that store can be added to indefinitely.

A store of memories however is subject to fire, deterioration and carelessness and, in the case of computers, changes of operating systems, hardware malfunctions and interoperability difficulties. So then, it is without any clear limit, but very fragile.

And knowledge of how the universe actually works? Karl Popper tells us that we cannot prove our theories to be true, but our scientists nonetheless carry out experiments, for example to test increasingly impenetrable hypotheses with a view to solving the contradiction between quantum theory and relativity theory. How much shall we progress as humankind? Unfortunately, we cannot say what we will know – it would mean that we already knew it - so then in itself a major limit to our knowledge.

Our knowledge of how the brain works, is though, improving. It tells us that the data we receive from our sense organs informs our brain as to what is going on, and the brain then creates the model of the external world to which it responds. Our conscious brain produces a working image of it for us.

But the brain’s functioning can lead to unexpected results. Some years ago, scientists reported an experiment they carried out on a blind man. He was blind because he had had a stroke which had damaged the part of his brain which enabled him consciously to see things. His eyes and the optic nerves were unaffected, as was the part of the brain to which the optic nerve reported.

They put him in a room with lots of things in it and asked him to walk across it. He succeeded in doing so without colliding with any of the obstacles. He was unaware at a conscious level of having seen anything, but his sub-conscious brain had ‘seen' everything and guided him accordingly. So then, the image normally produced for his conscious mind was not strictly necessary.

And, when you think about it, we are not surprised when we walk down the street without making any conscious effort either to walk or to avoid collisions with other people. But of course, babies don't do that. They have to learn to walk, to take avoiding action. But they soon sub-contract that work to the sub-conscious so that they can get on with other things. And it seems that those other things include not only the motor tasks which we have to manage in order to stay upright, but also, at least in part, the higher, rational activities that we need to engage in order to determine the meaning of life, the universe and everything.

After many years of study and of practice of the law, the mere presentation to me of a problem would normally automatically bring to the fore at least the outlines of its solution, presumably from my subconscious. That in turn would suggest to my conscious brain how to investigate further and then by combining my ‘background knowledge' together with the consciously acquired new data from e.g. the case-law I consult, the most likely solution would gradually emerge into my conscious brain. Apparently that's how it happens.

Functional magnetic resonance imaging has apparently come a long way and now it really is possible not only to localise where different functions of the brain take place, but also to see them take place in response to external stimuli. In this way a picture has built up which tells us that we are very different to how we normally perceive ourselves, because now it seems that in fact the vast majority of processing goes on at a sub-conscious level, with only occasional reporting back of the results to the conscious mind. This is true of what we would see as intellectual tasks as well as everyday things.

We see this in doing the crossword, where we look at a clue and have no clue as to the answer. Give it ten minutes and, preferably, a complete distraction, and then the answer becomes blindingly obvious (sometimes!). Likewise, we go to sleep unable to see an answer to a problem only to wake up with a much clearer picture of how to deal with things. From the research carried out, it seems that it is both when we are awake and also when we are asleep that our subconscious is beavering away to produce solutions. It never shuts down.

So what exactly does the conscious me do? The latest research suggests that the sub-conscious is processing all the information we take in, but the conscious brain (the ‘mind') decides what information it actually needs for what it has determined is required for its purposes. It then extracts that information from the basement level. In other words, current theory is that the conscious brain is there to manage things. It is there to keep records and plan; to keep to the fore a picture of who we are and what we want to achieve.

Unlike other animals, we have long term goals other than simple survival. They involve change in our lives, sometimes radical change. And for these to come to fruition it is reasonable to assume that it is efficient for us to be more than just dimly aware of ourselves as entities. In order to plan for the future, we have to see ourselves as part of a process in time - to imagine ourselves (consciously) in our planned future. To interact socially and so co-operate as successfully as we do with others, we have to be able to recognise them as beings similar to ourselves and understand how they think. We have to be able to stand in their shoes. We must be fully self-conscious.

And in all of this, is there a place for a mind separate from the brain? There seems to be no need for one according to the scientists. But for those who still think there is one, I wonder how they would explain Alzheimer's disease? The dualist's non-material mind is supposed to be the real me and so allow ‘me' to continue into eternity. With Alzheimer's, however, the progressive loss of  memories is accompanied by a loss of personality, the loss of ‘me'. To the dualist it must seem an unwelcome coincidence that a brain disease can mean that the non-physical mind parallels the physical brain's decline, so that there is essentially nothing left of the real me to go onto the next life - neither personality nor memories. You would think that my eternal spirit would have a back-up copy of me to use in case of emergency.

Paul Buckingham

15 August 2023