© C.O. Evans
 We may usefully compare the function of the word 'conscious' with the function of the word 'colour'. Often we are simply interested in the fact that something is coloured, or has colour, without being interested in which determinate colour it has. And yet we do not on that account imagine that an object can be coloured without being of a determinate colour, or of a number of determinate colours. What is true of the word 'colour' is also true of the word 'conscious' as I have defined it. A person cannot be conscious without its being true that he is either perceiving, or having thoughts, emotions, etc. In this sense 'conscious' and 'consciousness' are, as Mill says, generic terms.
I wish now to offer an explanation of the advantage of this generic term, which to my knowledge has not been fully appreciated. In the passage of James Mill's which I have just quoted he said in this regard, 'It was of great importance, for the purpose of naming, that we should not only have names to distinguish the different classes of our feelings, but also a name applicable equally to all
those classes.' He does not, however, tell us what its importance is. Perhaps he took its importance to be obvious; perhaps it is. There is, however, one respect in which the importance of having the generic term 'conscious' is not obvious, and this respect is of philosophical importance. It can best be brought out by returning to the comparison of the generic term 'conscious' with the generic term 'colour'
An expanse of colour may be comprised of one particular hue or several. If the former, then the particular hue exhausts the colour of the expanse. If the latter, then the sum of the particular hues exhausts its colour. The existence of colour is nothing over and above the existence of particular hues of colour. We may think of a multi-coloured expanse as built up of a mosaic of individual hues. Now there is a temptation to think of consciousness in this way too, and to assume that if it is a condition of being conscious that a person must have one or more determinate experiences, then his consciousness is identical with the sum of such determinate experiences; consciousness being conceived of as a mosaic of particular experiences, as it were. On this conception when a subject specifies the particular experiences he is undergoing at a particular time, he exhausts the description he gives of himself as conscious at that time. In other words, to say that a subject is conscious is just an abbreviation for saying that he is either seeing such-and-such, or hearing such-and-such, or thinking such-and-such and so on through all the 'particular classes of our feelings' as Mill describes them. Obviously this list should not be understood disjunctively: a number of these determinate 'feelings' can occur simultaneously. It is usual, for instance, to see, hear, and think contemporaneously. An implication of viewing consciousness in this way would be that it would entitle us to draw the inference that if we took a sufficiently short time span we should be able to specify all the individual 'feelings' that together make up a particular consciousness during that time.
In other words if 'consciousness' is the name of a class of mental 'events', then it must be possible to define the class extensionally by denoting all the members belonging to it. If such were the case, there would be complete logical parity between 'conscious' and 'colour' considered as generic terms. This view of consciousness may fitly be described as the mosaic view of consciousness. This is the model of consciousness that underlies the classical atomistic theory of consciousness.
I shall argue that this mosaic view of consciousness is false, and that the assumption of parity between 'conscious' and 'colour' breaks down. My rejection of this view constitutes my most important divergence from the traditional empiricist view of consciousness.
Let us imagine setting out to draw up a list of all the feelings of which a person's consciousness is made up during a time-span of a few seconds- - cashing the consciousness for the real coin of thoughts, feelings, perceptions, and desires. The job would be completed when we had entered the very last 'feeling' on our list. This can be most effectively illustrated in the case of visual perception. At the moment specific objects are in my visual field: I see various things, each of which must be entered in my list as a particular perception. I at once notice a disconcerting development. The more I look, the more 1 see. When the separable objects seem to have been exhausted, I can pass on to noticing irregularities in the surfaces of the objects, marks, shadows, and other details. I soon realize that my description of what I see can go on indefinitely. I cannot exhaust all there is to see in my visual field. It is the source of as many different perceptions as I care to have. At least in the case of visual consciousness, therefore, it is not the case that consciousness is equivalent to a determinate set of constituents.
Now it may be argued that under normal circumstances we are not busy probing our visual fields to discover how many different things and aspects and properties of things we can spot. Normally there are just a few things which hold our attention, and these are what we see, and these are determinate. This I concede, but it does not save the position. I will see a few objects in the centre of my visual field discretely and separately, and no doubt they will be the first to go down in my list. But what of the remainder of my visual field? Can I be sure that it is also furnished with equally distinct and separate objects? Is it not more probable that towards the borders of my visual field there is a penumbra within which it is impossible to distinguish separate objects? Could I not find out by having a look, It is logically impossible to do so for two reasons:
(a) because if I focus my eyes on the borders of my visual field, I of necessity alter my visual field, thus destroying one of the conditions of the experiment, and (b) because the question is to discover whether what we see and to which we are not paying attention, breaks up into discrete objects in the same way as does the visual area to which we are paying attention. Here too it is logically
impossible to verify the claim that the objects to which we are not attending are as clear and distinct as those to which we are, because in order to do so we have to attend to the parts of the visual field which were previously unattended to. But then they become objects which are attended to, and they cease to be the objects we wanted to find out about: i.e. objects which were not being attended to.
I have gone far enough, I feel sure, to demonstrate the completely unrealistic nature of the assumption that visual consciousness is made up of a distinct and separable set of constituent experiences. When an item is picked out of the visual field and described in some such statement as 'I see a tree' we must realize that under normal conditions we at the same time see vastly more than we describe.
Of course in this connection visual consciousness is a rather special case, 23 and it is not as clear in the case of other forms of perceptual consciousness that we cannot exhaustively describe what enters the sense field in question. When the content of the sense field is rich (as in the auditory field would be the case if one were listening to an orchestra) the situation is analogous to the visual field, but often the sense field is impoverished (as in the auditory field would be the case if one heard but a single sound) and then the analogy breaks down. Nevertheless this counter-instance is not serious for a variety of reasons. Firstly, although my examples are confined to single senses, our list cannot be so confined if it is to exhaust the 'feelings' that go to make up consciousness. The position would only be serious if it were possible for all the sense fields to be impoverished at the same time. This is not likely to happen outside a psychological laboratory, and even then it would not be decisive. For, secondly, if we classify the somatic field as falling under perceptual consciousness- - and for the present purpose we may - then at least the somatic field is always rich. (I would not know what it would be for the somatic field to be impoverished short of general anaesthesia and then we would no longer be dealing with consciousness.) In short although unusual circumstances may be conceived in which it might be possible to give an exhaustive description of the constituents of an impoverished consciousness, it would definitely be false to claim that under normal conditions such a description can be given of consciousness.
I have confined these remarks to perceptual consciousness because it is not as obviously true of non-perceptual consciousness
- thinking, reverie, imagining- - that its constituents cannot be exhaustively described. I shall not deal with this complication because I shall later dispose of the point by arguing that non-perceptual consciousness is dependent on perceptual consciousness. lt will not matter, therefore, should it not be the case that the constituents of non-perceptual consciousness are similarly unenumerable. I shall have much more to say on this subject in succeeding chapters however; for the present purpose 1 hope I have established that there is a logical disparity between the generic terms 'conscious' and 'colour', and that it is the peculiar merit of the terms 'conscious' and 'consciousness' that they convey the true impression that our lives are at every moment packed with a dense amorphous conglomeration of experiences, or 'feelings' as Mill called them. No matter how full we make our description of what we are conscious of at any one time, this will always be the merest sample of the mass of feelings, which go to make up consciousness at that time. Anyone wishing to focus attention on this particular aspect of the mental will find himself seriously handicapped if he tries to dispense with the term 'consciousness'.