[Image] WESTERN PHILOSOPHERS have pondered the questions of 'what is knowledge?', and 'what is truth?' for centuries. Without, it must be said, coming to any kind of consensus. And without, it seems to me, acknowledging that the inability to come to a consensus after many centuries says there is something terribly wrong with the whole enterprise of philosophy! The question of why two philosophers can never agree is part of a larger question that interests me. On the surface there seem to be very different modes of knowing and processing knowledge. We distinguish intellect from feelings for instance, and reasoning from intuition. We have always insisted that the differences are important and have often valued one over the others. The classic contest is between reason and emotion. But some research (now decades old in fact) raises the question of whether these are even valid categories when it comes to knowledge.

I've already mentioned, several times, a case study cited by Antonio Damasio in which he meets a patient with damage to his ventro-medial pre-frontal cortex (red in the image). This part of the brain is involved in the regulation of emotions. Emotional impulses typically come from deeper brain structures in the so-called Limbic System; a series of related structures in the lower and mid-brain. However emotions are also processed and regulated by our neo-cortex. In the patient mentioned by Damasio his awareness of emotions is extremely attenuated. Asked to describe his journey to the appointment his emotional tone was flat, even when describing the traffic accident he witnessed along the way. The emotions do not register. But his narrative shows that his powers of observation and understanding are not impeded; for example his recall of the trip is detailed and the facts are accurately related. He understands cause and effect. What is missing is the emotional response. And this shows when the patient is asked whether an appointment on Tuesday or Thursday next week would suit him better. He has a complete grasp of the facts relating to the choice - his and other's schedules, traffic conditions at different times etc, and he understands the task: but after 30 minutes of reviewing the facts he cannot come to a decision. The facts appear to be evenly weighted in his mind. Each fact is as important as every other fact. So that he has no basis on which to make a decision. (Descartes' Error. p.192ff.) (see also Grabenhorst & Rolls, van den Bos & Güroğlu).

This points to a very important conclusion: that facts alone are not the basis of how we make decisions. We need to know the relative value of each fact, and this information comes from the emotional response we have in relation to the fact. When we consider the facts we don't just decide what we believe to be true. In any given situation there are likely to be hundreds of true facts. We need to decide, given the context, which facts are relevant and important, i.e. salient. Facts make for sense, and emotions make for salience. We simply cannot make decisions without both.

Salience is terribly important. I recently learned for instance that schizophrenia is going to be renamed salience syndrome in the DSM-V (The DSM Diagnostic and Statistical Manual of Mental Disorders, 5th ed. due out next year) The current thinking is that a person with the disorder assigns the wrong level of salience to their experience which leads to delusions. Cause and effect can become confused or disconnected, and coincidences start to take on far too much salience. Inner experience can seem as though it is connected to external events in ways that only the sufferer can detect. An urge to act may not be felt as coming from 'me' so must be coming from outside. And so on. Schizophrenia means 'split mind' (though the etymology of Greek phren 'mind' is unknown), which is not at all descriptive of the disorder and has often lead to confusion amongst lay people. Correctly assessing the salience of our experience is virtually a definition of sanity, though the definition has a broad and ill-defined boundary.

So part of the reason that philosophers (or people generally) cannot agree on things is that we have different notions of value and salience, and since these are primarily emotional they are difficult to articulate. In fact we tend to unconsciously absorb the values and notions of salience from the people around us. Values are strongly conditioned by relatives, friends, race, region, and religion (i.e. by all the various groups we are members of). Attempts to articulate universal values have so far failed to convince everyone. The problem of inarticulate values is exacerbated by those aiming at what they call 'rationality' or 'objectivity' since this usually involves consciously suppressing emotional responses.

Incidentally, this shows that unless the Vulcans of Star Trek were wired very differently from humans, that Mr Spock & co. would have been unable to make decisions. Without a way to assign value to facts they would all be just like Damasio's brain damaged patient.
Intuition and Reason
People I know have been using the term 'intuition' a lot lately and have consistently failed to respond to my request to know what they mean by it. I think I'm in a position to offer a definition which demystifies the word. Let's start with reasoning. In reasoning, as I have indicated, we don't just manipulate facts to make sense. In reasoning we tap into emotions to give value to facts, and then compare the relative values to decide which is salient, or which is most salient. Saliency is a much more fuzzy concept than truth. We know that two intelligent people can reasonably come to opposing conclusions given a set of facts. This is the basis of of arguments in politics and well as philosophy for example. It's so much a part of our daily lives that it hardly needs an example, but the classic illustration is between conservative and liberal politics. Given identical facts, right and left leaning people will come to completely different conclusions about appropriate courses of action, because each assesses the salience of competing facts differently. (The different values of left and right are summarised very well in a diagram produced by David McCandless and Stefanie Posavec for the Information is Beautiful website. See also McCandless on TED) The irreconcilability of left and right rests not on the facts per se, but on what each side considers to be the most salient facts. This is true of the irreconcilability of philosophies, ideologies, and religions also.

The champions of reason initially saw it as a way of freeing us from superstition. The great discovery of the Enlightenment was facts that were apparently independent of belief systems (though geometry was known to have this property since antiquity). Gravity affects the Atheist and the Christian in precisely the same way. If we measure the acceleration due to gravity anywhere on the earth then it is about 10 ms-2 with a variation proportional to our distance from the centre of the earth, and the density of the material directly under us, and a margin of error. In a world where most conflicts are based on mutually antagonistic belief systems this revelation from science seemed to be incredibly valuable. The hope was that we had discovered a reliable way to make decisions, and there were things we could all agree on! Some people still see science in this light, but most of us now acknowledge that values play a role in science as well. Though of course some religieux still fail to acknowledge facts that conflict with their (highly valued) belief systems.

Reason came to be associated with the conscious manipulation of these facts divorced from emotional involvement. And the Romantics (over) reacted to this by revalorising emotions at the expense of reason (leading Romantics tended to break with the values of the society around them). Unfortunately there is a great deal of difference between a value independent fact (like gravity), and value independent thinking (which amounts to suppressing one's awareness of emotions and therefore empathy). We still have to decide what facts are relevant to any situation, and all too often empathy is left out of rational equations. Cold reason has caused atrocities every bit as wicked as unchecked emotions have.

So reason, it seemed, could free us from superstition. Obviously it has failed to do so. Why? It could only have succeeded if the supernatural had low salience for us. In fact supernatural thinking tends to have a high value, and therefore high salience for many people I know (C.f. On Credulity), and though they are a bit credulous they are by no means cretinous. The survival of the supernatural is partly due to the pernicious influence of the Romantics who celebrated the irrational, but of course they only tapped into something that already existed in the hearts and minds of people. There is a very great reluctance to abandon the supernatural, many of us value it, and continue to find it salient in understanding our experience. People who rail against religion (often to a highly irrational extreme, marked by very strong emotions) on the whole seem to be ignorant of this dynamic, making their criticisms unhelpful (and I'm specifically thinking of Richard Dawkins here).

Which brings us to intuition. Unlike reasoning where we try to consciously compare the values we have assigned to facts, intuition is the same process undertaken unconsciously. Experientially it seems as if we leap to a conclusion, or the answer to a problem appears as if from nowhere. We tend to be quite naive about this and since we don't see a process, we assume that one doesn't exist or that it is a bit magical. Intuition then becomes mystified. All that is happening is that we are weighing the value of facts subconsciously and coming to an unconscious decision. It may also be that our phenomenal ability to detect patterns operates better at an unconscious level, since it it something we developed early in evolutionary terms (other animals also use pattern recognition to help them survive).

It may even feel as though trying to think consciously about a problem is counter-productive. Perhaps this is because we cast the net too widely and overload our judgement of salience with too many facts; or perhaps our intellectual (or ideological) values actually conflict with our unconscious values; or perhaps we are just alienated from our body and emotions which makes are values difficult to access. In any case often we solve a problem by allowing ourselves to work on it unconsciously. Many of the great advances in science have come through allowing the problem to mull over unconsciously. Breakthroughs often come after a night's sleep and have even come in dreams (like the structure of the benzene molecule). There's nothing very mysterious about this process, and in many ways it is simply the same as "reasoning" - connecting facts and/or experience, to emotions and values, to decide what makes the most sense of the given facts under the circumstances.

It seems to me that a number of fallacies about how we think persist in spite of new evidence which is constantly emerging. Folk ideas about the mind are still in the process of assimilating the ideas of the 19th century psycho-analytic movement and it's more popular spawn, let alone the insights of neuroscience. As I understand it there is no fundamental difference between reason and intuition, they are the same process operating at different levels of awareness. There is nothing magical about intuition (I frequently rely on it), though the unconscious nature of it does lend itself to magical explanations.

In a sense the magical explanations of intuition are rather egocentric: 'I' am the owner of all that I'm aware of in my mind and body, and since intuition is unconscious it must be 'not I'. And being both 'I', in that the inputs and outputs happen in my mind, and not 'I', in that I am unaware of the process of producing the output from the input: then something super-natural must be happening.
Embodied Cognition Another fallacy about reasoning is that it is wholly abstract and divorced from experience. George Lakoff and Mark Johnson have showed that this is not so. Lakoff and Johnson have showed for instance that when we think abstractly we employ metaphors which draw on our physical experience of being embodied. We employ metaphors like UP IS GOOD/DOWN IS BAD. So if the stock market 'rises', then that is a good thing. But the stock market is only a notional entity and is not able to move about in space. Our reasoning here depends on the experience we have of moving about in space with our bodies. UP IS GOOD is likely related to an upright position being consistent with life, and lying down with death. And note that UP is not always GOOD. When we have a "high" fever this is a negative. Temperature being "high" or "low" is also a spatial metaphor (perhaps related to the position of the sun in the sky).

If I say "a thought just came into my head" I am performing quite a complex metaphorical translation. I am employing a range of metaphors: thoughts are objects, thoughts are agents, my head is my awareness, my head is a container--therefore awareness is a container). I'm relying on my experience of placing objects into containers, without which the sentence would not make sense. I'm also placing my first-person perspective inside that same container. The thought has to enter the same container, because containers can also hide objects. The unconscious is a container I cannot see into for instance. And note that the thought is an autonomous agent - it comes into my head, without me willing it (c.f. my previous statements on intuition). Although we all have an experience like this, the expression is metaphorical. Even apparently simple statements of fact are often couched in terms which rely on a complex interlocking system of metaphors that ultimately depend on how we physically interact with the world.

This argument from linguistics is confirmed from a neuroscience angle by the existence of mirror and canonical neurons, which form part of the motor cortex. When we do an action, say clenching a fist, parts of the motor cortex are active. Mirror neurons are active when we see someone else perform an action. Canonical neurons are active when we are presented with an object, or an image of an object, and we imagine how we might manipulate it. It is an unsurprising conclusion that we relate to the world in terms of how we might interact with it or manipulate it. However these same interactions form the basis of the metaphors that we use in abstract thought, which is not generally recognised.

Reason, then, is very much embodied and abstract thought depends on metaphors arising from our physical interactions with the world. Reason relies on assessing the salience of a fact by connecting it to our emotions, which we experience as bodily sensations. Reason also relies on metaphors and abstractions which are based in how we physically interact with the world. When we consider the nature of belief we need to keep all this in mind. A belief is a proposition that we have decided is not only true, but which has great salience. To shift a belief by offering alternative truths is ineffective. One can only shift a belief by changing the relative importance of the facts - that is by addressing salience. Indeed if we hold something to be highly salient, then the "fact" that it is untrue might not be salient - and we can comfortably and tenaciously believe untrue propositions. I would say that it is frequently the case with fundamentalist religious beliefs. In a future essay I want to look at how scientists have failed to communicate the salience of evolution, and allowed some religious people to continue to deny it despite the "facts". This is paralleled by Buddhist responses to the demonstrable fact that rebirth is factually implausible.

~~oOo~~
Bibliography Damasio, Antonio. Descarte's Error. London: Vintage Books, 2006. Grabenhorst, Fabian & Rolls, Edmund T. 'Value, pleasure and choice in the ventral prefrontal cortex.' Trends in Cognitive Sciences. 1 February 2011 (Vol. 15, Issue 2, pp. 56-67) doi:10.1016/j.tics.2010.12.004 Lakoff, George & Johnson, Mark. Metaphors We Live By. University of Chicago Press. van den Bos, Wouter & Güroğlu, Berna. 'The Role of the Ventral Medial Prefrontal Cortex in Social Decision Making.' The Journal of Neuroscience, June 17, 2009 • 29(24):7631–7632. DOI:10.1523/JNEUROSCI.1821-09.2009 van Os J. 'Salience syndrome' replaces 'schizophrenia' in DSM-V and ICD-11: psychiatry's evidence-based entry into the 21st century? Acta Psychiatr Scand. 2009 Nov;120(5):363-72.
Comments are open again, let's see how I go.