Introduction

Colour appears all around us. From the blue of the sky to the green which dominates the natural world, and the bewildering diversity of hues displayed by flowers, fruits and animals. What is common to all occurrences of colour, however, is that each individual instance is extremely simple. The field of red visual quality apparent on the exterior of tomatoes, for example, does not contain any distinguishable elements or structure. One consequence of such simplicity is that the contrast between the appearances of different hues – red, green, blue, yellow and so on – is maximized and the chromatic variety offered to us by the surfaces of the world is as great as it could possibly be. Another consequence is that colour provides one of the most basic forms of content contributing to the appearance of the world. The other forms of content that make up the appearance of the world are the remaining sensory qualities, of sound, smell, taste, cold and warmth. These too are equally simple in nature. Thus individual occurrences of the aroma of baking bread or the sound of a firework exploding are – along with colour – as simple entities as one will ever encounter in the universe.

Yet despite their significance as providers of content, and their ubiquity, man has yet to achieve an understanding of the nature of the sensory qualities. This is remarkable given their simplicity – they hardly present the technical challenges of complex objects such as brains or galaxies, which contain billions of components (nerve cells and stars respectively). It is all the more extraordinary, too, in the present age, when scientists have developed their discipline to the point of being able to explain events in the physical world at scales of structure ranging from the interior of the atom to the entirety of the cosmos. The position is somewhat analogous to that which notoriously obtains in the field of medicine regarding the ‘common cold’. Just as this most widespread and down-to-earth of afflictions remains incurable while treatments have been found for more esoteric diseases, so here the simplest feature of the physical world, and that which has the most direct impact on man, remains a mystery while nature’s most complex structures are steadily being laid bare.

Of course, science has revealed a great deal about the events that usually occur in the material realm when sensory qualities are also present. Physics has told us about the nature of electromagnetic radiation (‘light’ as we call it when it vibrates at frequencies that our eyes can detect), which reflects off objects when they appear coloured, and radiates from them when they feel hot. Also about the sound-waves that in a similar way are associated with the quality of sound. Chemistry has revealed the makeup of molecules which, when they diffuse through air, give rise to smells. But there is no prospect of the disciplines of science shedding any light on the mysterious nature of the sensory qualities themselves – the blueness that we see in the sky, the sound of leaves heard rustling in the wind, and the warmth felt as given off by a crackling fire. This is precisely because of their simplicity and content-providing nature. For these characteristics make the sensory qualities quite unlike the types of entities that science is capable of dealing with.

In contrast to, say, atoms which are made up of an internal structure of component particles such as electrons, neutrons and protons, entities like the colour red (as we have just seen) and the smell of thyme possess no structure and hence have no measurable or quantitative features. But not being quantitative or measurable they cannot become subject to the mathematically-based (therefore quantitative) forms of theorizing that prevail in science. For the same reason no instrument could ever be built that was able to detect the sensory qualities (as distinct from the signals such as light or sound-waves, which are associated with them) so they could never be investigated through science’s experimental procedures. In short, the sensory qualities are invisible to everything in the scientist’s tool-kit. The combination of super-simplicity and content-provision that characterizes the sensory qualities – often referred to by saying that colours, sounds and so on are ‘qualitative’ rather than quantitative – enables them to slip through science’s otherwise all-conquering ability to tease out the structures of reality.

If questions about the sensory qualities cannot be answered by science then the only means left for doing so is through the techniques of philosophy. If and when philosophers manage to answer them, we can expect the answers to have implications both in the arena of the ‘external’ physical realm and in that of the ‘internal’ mental one. This is because perception, the activity in which sensory qualities invariably arise, acts as a bridge between these two domains. It provides man with access to external reality. Inevitably, therefore, any consequences which follow from our coming to understand the nature of the most basic entities to arise in perception, will fall on both sides of that bridge.

But it has to be said that advances in achieving a philosophical understanding of the nature of the sensory qualities have occurred at a less than impressive rate.In one form or another, the question of the nature of the sensory qualities has formed a topic of consideration by thinkers (in East and West) for many centuries. Yet even now there remains little or no sense of movement towards a complete solution. Why is progress so restricted? The reason for this, I suggest, is the same as the explanation for philosophy’s poor performance in answering many of the questions which confront it. Arguably, the discipline is still in its Stone Age.
If my experience is anything to go by, what philosophers do when confronted by a problem is ‘sense out’ a solution to it. This is a lengthy and quasi-artistic procedure which is similar to how a painter or sculptor forms their work. It is also, no doubt, akin to the semi-intuitive procedure that would have been acquired, after years of practice, by Stone Age ‘nappers’ – who were, after all, the sculptors of their day – in order to strike a piece of flint in the correct way to fashion implements of utility.

In philosophy each new problem needs to be sensed out anew from scratch, just as a Stone Age napper faced with a fresh piece of raw flint would first have had to feel it all over before creatively applying his intuitive skills and working out at what angle and strength to strike it. Because the methodology is intuitive and creative, for both the Stone Age worker and the philosopher, each new problem demands an approach which, although it may build on skills acquired in previous attempts, cannot make any use of their products. It therefore forms a set of operations that is unique to the particular problem being faced and is never repeated for others.
This is all quite different from what happens in science, which through its use of mathematics for the development of theorems and standardized protocols for experimentation, is in possession of repeatable procedures that are applied again and again to every new problem that comes up. No-one would deny that there is also a significant element of creativity in science, but the foundation of its methodology – in contrast to that of philosophy – involves a set of procedures that are infinitely re-applicable to any problem that may be confronted. In this respect, extending to it the ‘pre-historical’ metaphor applied to philosophy, one may say that science is in its Bronze Age. Bronze Age metalworkers discovered how to combine a standardized ‘recipe’ of ingredients under heat to form bronze, and thereafter were able to repeat the same operation at will in order to produce metal ingots to order, just as scientists can repeat their standardized recipe of procedures at will in order to solve virtually any problem that may arise.

People react to the position in which philosophy finds itself in different ways.

Amongst the tribe of philosophers one notices, for example, endeavours to emulate some of the superficial features of science’s success, such as attempts to apply methodologies which have a semi-scientific ring to them, or the finishing of texts to a high level of technical language. Reactions such as these are somewhat like members of the unruly tribe of philosophers, jealously regarding in the neighbouring valley the metal swords and jewellery of the advanced tribe of the ‘Scientii’ glittering in the sun, taking to polishing their crude stone artefacts in a vain effort to try and achieve a similar effect.

Another possible reaction – of more significance – could involve the thought that if philosophy is perhaps only in its Stone Age then realistically it stands little chance of answering any of the questions which it has set for itself. But I would commend an alternative to this which offers a more positive way of looking at the situation. If the possibility exists that philosophy is currently only in its Stone Age then there are yet great tracts of discovery to be made and huge fields of development for the discipline to undergo in the future. After all, once it develops beyond its Stone Age philosophy will presumably be as different from the subject we know today as chemistry currently is from alchemy. So on this view the possibilities offered by the present situation are considerable and the chances significant that there may genuinely be answers ‘out there’ to many of philosophy’s questions.

In this book it is this positive outlook, and the associated attitude that philosophical questions are in principle answerable, that I have attempted to bring to bear on the problem of the nature of the sensory qualities. In trying to find that answer I have endeavoured to strike a blow at the ‘flint’ of the problem at an angle that to the best of my knowledge has not been tried before. Whether or not it has succeeded in revealing a form of answer that carries any worth will be for others to judge.