© C.O. Evans
 I come now to the question of whether it is ever possible to attend to more than one object at a time. We have seen how Hamilton, Ribot, and James agree that the natural tendency of attention is to 'narrow' or 'concentrate' the area of awareness. It is natural, and acceptable, for a person to excuse his failure to pay attention on the ground that he was forced to pay attention to too many different things at once. No one could offer as an excuse for his failure to pay attention the fact that he had only one thing at the time to which to pay attention. If it were not true that the restriction of attention was vital to its successful operation, we would not be able to explain how it was possible to have our attention distracted. For if we could equally well increase the number of things we attend to without our attention to any of the things suffering as a result, we would not be 'distracted' by the new things that had been drawn into attention. The facts of the matter seem plain enough, and I shall follow Hamilton in describing the systematization of these facts as 'the law of limitation'.
This law is, that the greater the number of objects to which our consciousness is simultaneously extended, the smaller is the intensity
Hamilton's law rests on the assumption that it is possible to pay attention to more than one thing at a time, and this enables a plausible explanation to be given of the existence of degrees of attention: the larger the number of things holding attention which are not connected, the smaller the degree of attention which is given to each. Quite apart from these aspects of the matter, however, Hamilton's law of limitation expresses well the fact that the more restricted, or narrowed, attention is, the more efficient it is. Logically, of course, the limit of such restriction is the case in which attention is paid to but a single object at a time. Those of Hamilton's contemporaries who, like Stewart, have argued against him that it is not possible to attend to more than one object at a time have no doubt been impressed by this fact. It has led to the belief that paying attention to a single thing is the paradigmatic case of paying attention. This belief has persuaded Stewart and others that if, in two instances, attention were narrowed down to a single object, the instances could not be concurrent: i.e. it would be impossible, by definition, to attend to both objects at once.
Many examples seem to bear out this contention. There is the well-known experience of trying to follow two separate conversations at once. What happens is that our attention 'jumps' from one conversation to the other, and we catch a phrase from this discussion and a point from that. We also find a tendency for attention to settle on one of the conversations at the expense of the other, so that we follow and understand more of the one than the other. Here we have an example of conflicting claims upon attention, and there is no doubt that it is a common occurrence to find claims on attention conflicting with one another in this way. But it is one thing for Stewart and others to be right in claiming that there are some cases of conflict of attention, and quite another matter for them to claim that all cases of attending to more than one thing at once are cases of a conflict of attention.
At first sight it looks as though the controversy could be settled by empirical means. It soon becomes obvious, however, that any counter-examples to the hypothesis that we only attend to one thing at a time can be nullified by the claim that even though we
are not aware of the fact, our attention nevertheless switches (too rapidly to notice) from the one object to the other. The rapidity of the movement from one object to the other would create the illusion that both objects were receiving continuous simultaneous attention; much as a spinning disc of different coloured segments gives the illusion of having one uniform colour. This is a classical case of a conceptual difference being mistaken for an empirical one.
The dispute is, I believe, a conceptual one, but it is also a sterile dispute. It cannot be settled unless and until we know what it means 'to attend to one thing at a time'. We need to know what 'one thing' is, before we know what the disagreement is about. And, I maintain, as soon as we know what constitutes 'one thing' we shall find that there is nothing left to dispute. Let us, therefore, enquire what it means to talk about an object of attention. How do we know that we are attending to one object and not several? The artificiality of this question can be brought out most forcibly by considering Sartre's example, in which the object of attention is the interior of a café. We can think of the café as one object, but the café in fact comprises a very large number of isolable objects. As Sartre makes quite explicit, the attender is aware of 'its patrons, its tables, its booths, its mirrors, its light, its smoky atmosphere, and the sound of voices, rattling saucers, and footsteps which fill it'. Because the attender is paying attention, all these things are 'taken in. But in a sense none of them are objects of attention. If, after-wards, the attender were asked to say what had been going on in the café, he might have only a hazy idea. He had been paying attention to the café, but not paying attention to everything he saw or heard in the café. He was not, in fact, paying attention to any-thing in the café at all! As Sartre correctly observes, it was as though the café scene were a 'ground' for a nonexistent figure. That is, it is as though attention were in search of its object of attention. Sartre makes this clear too. He says, 'If I should finally discover Pierre, my intuition would be filled by a solid element, I should be suddenly arrested by his face and the whole café would organize itself around him as a discrete presence.' Were that to happen, we would be in no doubt as to what the object of attention was - Pierre.
Sartre's statement that everything in the café would 'organize around' the object of attention is most important. Whatever it be that our consciousness 'organizes around' is that to which we are said to be attending. But even if Pierre had become the object of
attention, what constitutes 'Pierre' would be a number of different things. Pierre is still a complex object. Would that preclude him from being the object of attention? Surely it would be quite unrealistic to claim that Pierre could not be an object of attention on the ground that only the 'ultimate simples' of which he is composed (whatever that might mean) could be so regarded. There might be a variety of things I notice about Pierre as soon as I spot him. Are these features and not Pierre the object of my attention? And if they are, must I have noticed them one after another? We only need raise these questions to see that they presuppose putting a false precision on the whole matter.
A simpler example than Sartre's clinches the argument. Suppose we were asked what our several objects of attention are in relation to the appearance of the printed page before our eyes. Can we attend to several words simultaneously, or are we limited to one word, or perhaps one letter, at a time? If we can take in several words at a glance, would they be our object of attention? If so, would that mean that we had paid attention to only one thing, or several things at once? Or would it mean that we had successively attended to each individual letter? These artificial questions presuppose, I suggest, that there are such things as atomic objects, such that we could make decisions as to what is one object or another, quite irrespective of the purposes of the attender. We need only remind ourselves, however, how different the page must appear to an attender who is a proof-reader looking for misprints from its appearance to the average reader trying to follow the sense of the argument. The proof-reader might treat syllables as the objects of attention, while the ordinary reader might treat meaningful groups of words as objects of attention. Unless we know the purpose behind the attention, we cannot say what should be taken as the object of attention. The object of attention is attender-relative.