Philosophy

Twenty-three years have elapsed since William James startled the world with his article entitled “Does ‘consciousness’ exist?” In this article, reprinted in the volume called Essays in Radical Empiricism, he set out the view that “there is only one primal stuff or material in the world”, and that the word “consciousness” stands for a function, not an entity. He holds that there are “thoughts”, which perform the function of “knowing”, but that thoughts are not made of any different “stuff” from that of which material objects are made. He thus laid the foundations for what is called “neutral monism”, a view advocated by most American realists. This is the view advocated in the present volume. In this chapter, we have to ask ourselves whether there is anything that we can call “consciousness” in any sense involving a peculiar kind of stuff, or whether we can agree with William James that there is no “inner duplicity” in the stuff of the world as we know it, and that the separation of it into knowing and what is known does not represent a fundamental dualism.

There are two very different meanings attached to the word “consciousness” by those who use it. On the one hand, we are said to be “conscious of” something; in this sense, “consciousness” is a relation. On the other hand, “consciousness” may be regarded as a quality of mental occurrences, not consisting in their relation to other things. Let us take the first view first, since, in discussing it, we shall find reasons for rejecting the second view.

What is the relation we call being “conscious of” something? Take the difference between a person awake and a person asleep. The former reacts to all kinds of stimuli to which the latter does not react; we therefore say that the latter is not “conscious of” what is happening in his neighbourhood. But even if the sleeper does react in a fashion, for example, by turning away from the light, such a reaction does not fall within what is commonly regarded as “knowledge” or “awareness”; we should say that the sleeper turned over “unconsciously”. If he wakes up sufficiently to speak intelligently, for instance to address the disturber by name, we consider him “conscious”. So we do if we find that he remembers the incident next morning. But common sense does not regard any and every bodily movement in response to a stimulus as evidence of “consciousness”. There is no doubt, I think, that common sense regards certain kinds of response as evidence of some “mental” process caused by the stimulus, and regards the “consciousness” as residing in the inferred “mental” occurrence.

Sometimes, however, as in hypnotism and sleep-walking, people refuse to admit “consciousness” even where many of the usual marks of it are present. For this there are certain reasons. One of them is subsequent lack of memory; another is lack of intelligence in what is being done. If you offer a hypnotised patient a drink of ink, telling him it is port wine, and he drinks it up with every sign of enjoyment, you say that he is not “conscious”, because he does not react normally to the nasty taste. It would seem better, however, to say that he is conscious of the hypnotist and what he commands, though not of other things of which he would be conscious in a normal condition. And lack of subsequent memory is a very difficult criterion, since we normally forget many things that have happened to us, and the sleep-walker’s forgetting is only unusually complete. This is obviously a matter of degree. Take next morning’s memories in the case of a man who was drunk overnight. They become more and more vague as he reviews the later hours of the evening, but there is no sharp line where they cease abruptly. Thus, if memory is a test, consciousness must be a matter of degree. I think that here, again, common sense regards a certain amount of memory as necessary evidence to prove that there were “mental” processes at the time of the acts in question, acts in sleep being regarded as not involving “mind”, and other acts in certain abnormal conditions being supposed to resemble those of sleep in this respect.

It follows that, if we are to find out what is commonly meant by “consciousness”, we must ask ourselves what is meant by a “mental” occurrence. Not every mental occurrence, however, is in question. The only kinds concerned are those which seem to have relation to an “object”. A feeling of pleasant drowsiness would commonly count as “mental”, but does not involve “consciousness” of an “object”. It is this supposed peculiar relation to an “object” that we have to examine.

We may take, as the best example, an ordinary act of perception. I see, let us say, a table, and I am convinced that the table is outside me, whereas my seeing of it is a “mental” occurrence, which is inside me. In such a case I am “conscious” of the table—so at least common sense would say. And since I cannot see without seeing something, this relation to an “object” is of the very essence of seeing. The same essential relation to an “object”, it would be said, is characteristic of every kind of consciousness.

But when we begin to consider this view more closely, all sorts of difficulties arise. We have already seen that, on grounds derived from physics, the table itself, as a physical thing, cannot be regarded as the object of our perception, if the object is something essential to the existence of the perception. In suitable circumstances, we shall have the same perception although there is no table. In fact, there is no event outside the brain which must exist whenever we “see a table”. It seems preposterous to say that when we think we see a table we really see a motion in our own brain. Hence we are led to the conclusion that the “object” which is essential to the existence of an act of perception is just as “mental” as the perceiving. In fact, so this theory runs, the mental occurrence called “perceiving” is one which contains within itself the relation of perceiver and perceived, both sides of the relation being equally “mental”.

Now, however, there seems no longer any reason to suppose that there is any essentially relational character about what occurs in us when we perceive. The original reason for thinking so was the naively realistic view that we see the actual table. If what we see is as mental as our seeing, why distinguish between the two? The coloured pattern that we see is not really “out there”, as we had supposed; it is in our heads, if we are speaking of physical space. True, more than a coloured pattern occurs when we “see a table”. There are tactual expectations or images: there is probably belief in an external object; and afterwards there may be memory or other “mnemic” effects. All this may be taken as representing what the above theory took to be the “subject” side of an act of perception, while the coloured pattern is what the theory took to be the “object” side. But both sides are on a level as regards being “mental”. And the relation between the two sides is not of such a kind that the existence of the one logically demands the existence of the other; on the contrary, the relation between the two sides is causal, being dependent upon experience and the law of association.

If this is correct, what really happens when, as common sense would say, we are conscious of a table, is more or less as follows. First there is a physical process external to the body, producing a stimulus to the eye which occurs rarely (not never) in the absence of an actual physical table. Then there is a process in the eye, nerves, and brain, and finally there is a coloured pattern. This coloured pattern, by the law of association, gives rise to tactual and other expectations and images; also, perhaps, to memories and other habits. But everything in this whole series consists of a causally continuous chain of events in space-time, and we have no reason to assert that the events in us are so very different from the events outside us—as to this, we must remain ignorant, since the outside events are only known as to their abstract mathematical characteristics, which do not show whether these events are like “thoughts” or unlike them.

It follows that “consciousness” cannot be defined either as a peculiar kind of relation or as an intrinsic character belonging to certain events and not to others. “Mental” events are not essentially relational, and we do not know enough of the intrinsic character of events outside us to say whether it does or does not differ from that of “mental” events. But what makes us call a certain class of events “mental” and distinguish them from other events is the combination of sensitivity with associative reproduction. The more markedly this combination exists, the more “mental” are the events concerned; thus mentality is a matter of degree.

There is, however, a further point which must be discussed in this connection, and that is “self-consciousness”, or awareness of our own “mental” events. We already had occasion to touch on this in Chapter XVI in connection with Descartes’ “I think, therefore I am”. But I want to discuss the question afresh in connection with “consciousness”.

When the plain man sees “a table” in the presence of a philosopher, the plain man can be driven, by the arguments we have repeatedly brought forward, to admit that he cannot have complete certainty as to anything outside himself. But if he does not lose his head or his temper, he will remain certain that there is a coloured pattern, which may be in him, but indubitably exists. No argument from logic or physics even tends to show that he is mistaken in this; therefore there is no reason why he should surrender his conviction. The argument about knowledge in Chapter VIII showed that, accepting the usual views of physicists as to causal laws, our knowledge becomes more certain as the causal chain from object to reaction is shortened, and can only be quite certain when the two are in the same place in space-time, or at least contiguous. Thus we should expect that the highest grade of certainty would belong to knowledge as to what happens in our own heads. And this is exactly what we have when we are aware of our own “mental” events, such as the existence of a coloured pattern when we thought we were seeing a table.

We might, therefore, if we were anxious to preserve the word “mental”, define a “mental” event as one that can be known with the highest grade of certainty, because, in physical space-time, the event and the knowing of it are contiguous. Thus “mental” events will be certain of the events that occur in heads that have brains. They will not be all events that occur in brains, but only such as cause a reaction of the kind that can be called “knowledge”.

There are, however, still a number of difficult questions, to which, as yet, a definitive answer cannot be given. When we “know” a thought of our own, what happens? And do we know the thought in a more intimate way than we know anything else? Knowledge of external events, as we have seen, consists of a certain sensitivity to their presence, but not in having in or before our minds anything similar to them, except in certain abstract structural respects. Is knowledge of our own minds equally abstract and indirect? Or is it something more analogous to what we ordinarily imagine knowledge to be?

Take first the question: What happens when we “know” a thought of our own? Taking the definition of “knowing” that we adopted in Chapter VIII, we shall say: We “know” a thought of our own when an event in our brain causes a characteristic reaction which is present when the event occurs and not otherwise. In this sense, whenever we say, “I see a table”, we are knowing a thought, since an event in our brain is the only invariable antecedent of such a statement (assuming it to be made truthfully). We may think we are knowing a table, but this is an error.

Thus the difference between introspective and other knowledge is only in our intention and in the degree of certainty. When we say, “I see a table”, we may intend to know an external object, but if so we may be mistaken; we are, however, actually knowing the occurrence of a visual percept. When we describe the same occurrence in the words “a certain coloured pattern is occurring”, we have changed our intention and are much more certain of being right. Thus all that differentiates our reaction when it gives introspective knowledge from our reaction when it gives knowledge of another kind is the elimination of a possible source of error.

I come now to the question: Do we know our own thoughts in a more intimate way than we know anything else? This is a question to which it is difficult to give precision; it describes something that one feels to be a problem without being able to say exactly what the problem is. However, some things can be said which may serve to clear up our feelings, if not our ideas.

Suppose you are asked to repeat after a man whatever he says, as a test of your hearing. He says “how do you do?” and you repeat “how do you do?” This is your knowledge-reaction, and you hear yourself speaking. You can perceive that what you hear when you speak is closely similar to what you hear when the other man speaks. This makes you feel that your reaction reproduces accurately what you heard. Your knowledge-reaction, in this case, is the cause of an occurrence closely similar to the occurrence that you are knowing. Moreover, our inveterate naive realism makes us think that what we said was what we heard while we were speaking. This is, of course, an illusion, since an elaborate chain of physical and physiological causation intervenes between speaking and hearing oneself speak; nevertheless, the illusion re-enforces our conviction that our knowledge, in such a case, is very intimate. And it is, in fact, as intimate as it can hope to be, when our knowledge-reaction reproduces the very event we are knowing, or at least an event extremely similar to it. This may be the case on other occasions, but we can only know, with any certainty, that it is the case when what is known is a percept. This accounts for the fact that our most indubitable and complete knowledge is concerning percepts, not concerning other mental events or events in the external world. Our reaction to a sound can be to make a similar sound, and if we are clever enough we can paint something very like what we see. But we cannot show our knowledge of a pleasure by creating for ourselves another very similar pleasure, nor of a desire by creating a similar desire. Thus percepts are known with more accuracy and certainty than anything else either in the outer world or in our own minds.

The conclusion we have reached in this chapter is that William James was right in his views on “consciousness”. No mental occurrence has, in its own intrinsic nature, that sort of relational character that was implied in the opposition of subject and object, or of knower and known. Nevertheless we can distinguish “mental” events from others, and our most indubitable knowledge is concerned with a certain class of mental events. We have arrived at this result by following out to its logical conclusion the behaviourist definition of knowledge which we gave in Chapter VIII. We have had to modify considerably the point of view which originally led us to that definition, the modification having been forced upon us by the physical knowledge which, starting from a common-sense realism, has been gradually driven, through the causal theory of perception, to a view of cognition far more subjective than that from which physicists, like the rest of mankind, originally set out. But I do not see how there can be any escape from this development.