Space, Time and Deity
3: The Order and Problems of Empirical Existence
Chapter 5: Mind and Its Acts
Mental acts responses to objects
THE partners to the transaction which is called the relation of cognition are the act of mind and the non-mental object. The various orders of non-mental finites were described briefly so far as was necessary for metaphysical purposes in a previous chapter. All that was said of mind was that it was the substance of mental acts or processes. It is time now to describe these processes more explicitly, which we could not well do before, because the description of them is intimately dependent on distinguishing them from their objects. At the same time it was not possible to take over from the relevant science of psychology any well-understood and accepted statement of the nature of mental processes, for the foundations of psychology are at present involved with the theory of knowledge, treated as an independent science and not, as here, as a chapter of metaphysics.
There is no mental act but is correlative to its non-mental object ; the mind enjoys itself only as there is an object contemplated, which contemplation is the very act of enjoyment. A sensory object brings the mind into compresence with it ; an ideational act of mind puts the mind into compresence with its object, brings the object as we say before the mind. These facts have their analogues in the lower empirical levels. Mind stands nearest in the order to living organisms, and we have seen that vital actions either respond to external stimuli, or when they are provoked internally may relate the organism to some specially appropriate external thing, as
(117) when the drosera secretes the sticky substance which is to catch the flies on which it feeds. These specially preparatory processes may be peculiar to life and mind. But throughout finite existence there is no act which is not related to some other finite ; as I understand, within the atom there arc direct acts of initiative in the emission of rays which thus in a manner bring the atom into relation with other physical things. However this may be, however far down analogies to ideation may exist, every action either is the effect of something outside, or alters the relation of a finite to what is outside.
The mental act is thus the conscious response to some non-mental existent finite which is its object. I use the word response in order to avoid the word reaction, which it seems forced and unnatural to apply. For the organism is commonly said to react upon some actual or causal stimulus, and we should hardly describe the search for the absent food as a reaction upon the food, but rather as a reaction on the internal stimulus of depletion which sets the organism on its search. In the same way we cannot say that my remembering of a past event is a reaction upon the event remembered, for that event no longer acts causally upon my bodily organs. The recollection is evoked by and is a reaction to the internal stimulation, whether it is physical or mental, which suggests the recollection. In a stricter sense, however, the language of reaction to the object is unexceptionable. Though the internal stimulus causes the process of recollection, the form or pattern of the process is determined by relation to its object. For it is an acquired neural disposition whose character is defined in the main by the past actual or sensory experience. It is only the strangeness of the notion of reacting to a past or future event which makes us stumble, because we are possessed by the prejudice in favour of the actual (to use Mr. Meinong's phrase), and think that past and future are not real because they are not sensory. In truth, remembering and expecting are the reactions that are possible to a past or future object. At any rate mental acts belong to the class of vital reactions. But to avoid
(118) all these intricacies let us call the mental act the response to its object. What is essential is that there is no mental act without its appropriate object, and that this object is a distinct existence from the mental act, and may, as we have seen, exist without the mental act.
Mind made up of conations.
In the next place, since the object is an existence distinct from the mind and only selected by it, there is nothing in the mind (with a possible reservation to be made on behalf of feeling ) but acts. 'Act' in this usage is equivalent to process and does not imply the special activity which is felt in certain mental processes or acts like desire or endeavour or willing. It includes passive acts of sense as well as activities of volition. The term conation is commonly restricted in its usage to such active processes ; but in a more extended sense every mental act is a conation and is nothing else, except for the possible addition of feeling. It is equally legitimate to use the term employed by Mr. Ward  and to identify consciousness with attention. The word `conation' has the advantage, for it carries with it the meaning of practical action, and all mental action is primarily practical.
Now, cognition is not a separate kind of action from conation. It is not even a separate element in a mental act which can be distinguished from a conative element in the act. Cognition is nothing but the conation itself in so far as it is compresent with and refers to an object. We do not in perception have an act of cognition which leads to an endeavour towards the perceived object. The object is there and excites our sense and with it the suggested elements of ideation. This mental excitement, partly sensory and partly ideational, is a conation which issues in certain external bodily actions appropriate to the object. As issuing in such actions the act is conative. But this conation is itself that consciousness of the object which is called the perception. In behaving in certain manners towards the object we perceive it. And just as
(119) the animal goes in search of food, so in the act of preparation for the taste of the orange we forecast it in idea. Thus the perceiving act is nothing, but the perceptual, or impulsive conation itself, in so far as that conation which is partly touched off by the external thing itself, say the orange, partly by the supplementing mind, refers us to the object or the perceptum.
Illustrations might be multiplied indefinitely. We do not first perceive the apple to be a round red-cheeked thing which is edible, but we are aware of it as edible in and by the act in which we seek to eat it, which it provokes in us. In performing the mental act which ends in holding our hands so as to catch the cricket ball which is coming to us in a certain direction, we are conscious of the direction in which it is coming to us ; we do not first cognise its direction and then adjust our action to that ; it compels us to act in a certain fashion and we thus become aware of it. Simple sensation is a reflex act of attention evoked by the sensum (that is by the thing in so far as it contains the sensum), and referring to it. According as the sensum is red or green or sweet, it evokes by the light from it which acts on the retina, or the liquid containing it which acts on the tongue, a different reaction, which is the consciousness of the sensum. In so far as the conative act refers to its object it is a cognition. The cognitive element, therefore, of a mental act is, to use a paradoxical expression, not anything distinctive of the act as a process taking place in the mental substance itself, it signifies rather that the mental act refers to a cognitum. Thus the sensory conation is correlated with the sensum, the impulsive conation with the perceptum and the like. It is because in our mental acts there is an object revealed to us that we speak of the act as a cognition and not as a conation.
The reason why the cognitive aspect of the conation,
Practical and theoretical conation
(120) for it is nothing more than an aspect, not something existent which differs from the conation, comes to be separated from conations, is this. Conations are of two kinds. Primarily conation is practical, and it issues in movements which tend to alter or destroy the object or at least to affect our relation to the object. Thus the perceptual conation of perceiving an apple is primarily one which issues in movements of seizing and eating the apple. Or the outward movement may merely remove us from the object, as from a wolf, or bring us nearer to it, as to a fire in winter. But besides such practical conation, the issue of the conation may be suspended, as in merely watching the object. Here too the conation issues in movements, but they are not directed to interfering with the object but to sustaining our attention to it, that is to maintaining the conation as a mental process while inhibiting its normal reaction upon the object. Sometimes the outward movement is switched off into speech or other gestures. Such conation is to be distinguished from the other kind of conation as speculative or theoretical. Ultimately it grows out of the inhibition of the practically directed issue of our mental acts. We do not stretch out our hands to the stars in the childish impulse to possess them, but observe them with a telescope ; nor cower in terror under a solar eclipse, but observe the edge of the sun. When we have resolved neither to hate nor love mankind but to observe them, we have changed from the attitude of practical to that of scientific study of man. Thus speculative conation, or cognition, is isolated from practical conation by diversion or suspension of the practical movements which alter the world. We learn to alter ourselves and leave the object alone. But though we call the second speculation or science or knowledge, there is no difference in the mental act so far as it is directed towards the object. The difference lies in the whole interest of the mind, which in the one case leaves the conation to its normal course, and in the other inhibits its normal issue or diverts it into speech, or to the suggestion of fresh conations which have their objects in turn, that is, leads it on to a train of ideas.
(121) It is of the last importance for psychology as well as for metaphysics to recognise that the object is cognised in and with the conation, and that we do not first cognise and then act, but know in acting. But our acting may take divergent courses. We do not do because we know ; but we know because we do, and we end by knowing without doing. Yet our mental action, whether speculative or not, remains to the end a doing.
Thus of the two, cognition and conation, we must abandon one or the other, if we are attempting to describe what our mental acts are in the mental substance. Either, because there is an object which we cognise we must call mental action nothing but cognition (I defer feeling), and then conation merely marks the fact that all such mental process issues in movement of some sort which may be purely external, non-mental, bodily movement ; and always sooner or later after even the longest train of ideas does end in such movements. Or we must maintain that the mental act is a conation, which is something mental, and not merely physiological, and then cognition is simply the reference of this act to what is non-mental, that is to the object without which it is meaningless. I prefer the latter alternative as a statement of the truth. For it lays stress on the practical character of mind and brings mind into line with all other finites, like life and lower orders of being, the essence of whose life is to be movement. The word cognition ' of itself suggests passivity, or at least is far from appropriate to a process whose being lies in its outward direction to a non-mental thing. Practical action becomes an accessory of cognition ; whereas in truth cognition taken alone is an outgrowth and arrest of practice. I shall therefore say that mental action is conation, and that cognition is the aspect of it which I have thus so often described. But cognition has no claim to be regarded as a separate element in any mental act ; it is not another sort of mental attitude from conation. The real distinction lies in the two different subclasses of the one class conation.
Cognition is then nothing but conation as considered in its objective reference. Perceiving is seizing without
(122) its practical motor issue. Expecting is reaching out in speculation to the future ; remembering, as has before been indicated, is reaching backwards in speculative desire to the past. Judging or the apprehension of a judgment or proposition is willing in its mere objective reference : when I will to go to Glasgow, the object of my will is the proposition I am going to Glasgow ; when I judge the earth is round I am willing so to treat it, in a case where the outward issue of my willing is speech or the setting in motion of a train of free ideas. To this particular illustration, the identity of judging and volition, we shall have occasion to return. Greater detail is out of place in a metaphysical inquiry. It is the business of psychology and I have endeavoured elsewhere to supply a sketch of a psychology so conceived, to which I can now only refer.
This result would be simple and satisfying were it not for feeling, which is commonly regarded as a third element in all mental process with cognition and conation. The claim of cognition has now been dismissed. But what is to be said of feeling, that is of pleasure and pain, and whatever other kind of excitement we may reckon under this head ? What feeling is, is without doubt the obscurest elementary question of psychology. Feeling is certainly not a categorial character of mind but an empirical one, and it is certainly closely connected with conation ; so that it has been linked together with conation under the name of interest, and set against the second element of cognition. Some have even gone so far as to regard feeling as what is distinctively mental, to which conation, if its existence is admitted at all, becomes secondary. The metaphysical probabilities are against such a doctrine, which cuts off mind from its alignment with other things.
As an independent element in the analysis of a mental
(123) process or even as a mere toning of cognitive experiences, as it is often represented to be, there seem to be insuperable difficulties in the way of insight into its real nature. Feeling so regarded seems to repeat the characters of the sensory process to which it is attached, except for the disputable feature of differences in quality ; it has intensity, duration, and at least some degree of localisation. Its " parasitical " nature seems to be thus clearly indicated. The most satisfactory conception of it upon these lines treats it as arising somehow in the course of a conative process, according as the conation, or the underlying neural process, moves smoothly to its end or is obstructed. In sense-feeling pleasure attends the mental return to equilibrium after the mind has been disturbed by the sensory stimulation ; pain means impediment to this return. The theory is founded in its modern form largely on the pleasure and pain experiences of mental functions higher than sensation, such as the pleasures or pains of gratified or disappointed expectation, the pleasures of harmony or pains of disharmony in aesthetic composition, or the simpler pleasures which arise from harmonious blending of two colour sensations. The theory in respect of simple sense-feelings is an extension downwards from these higher integrations. On this view feeling still is parasitic to conation, and conation would still claim to be the dominant feature of mental life.
But many considerations tell against this conception and suggest that the clue must be found, if it can be found, in the sense-feelings themselves instead of the higher feelings. In general sense-feelings appear to follow the character of sensations. They are localised, sometimes very imperfectly, but sometimes quite definitely, in certain organs of the body. Sometimes indeed they are so diffused that we are apt to regard them as being purely psychical rather than bodily. Yet there is little but their want of specific character, I mean that pleasure and pain belong to any kind of sensation, to mark them
(124) off from the order of the organic sensations, such as hunger and thirst. These might at first sight seem wholly psychical, but we have no great difficulty there in distinguishing the bodily affection of hunger from the psychical awareness of it. In the same way we can distinguish pleasure from the consciousness of it. Thus the direct experience of pleasure and pain seems to fall in with what is suggested by the theory that there is nothing in mental acts but consciousness or conation, namely, that feelings are objective experiences of the order of organic sensa. Such sensations as I shall point out in the next chapter are experiences of the bodily life, as distinguished from the body as a merely physical thing, and the suggestion both of the facts and of theory is that pleasure and pain are not mental modifications but characters of life of which the mind has awareness, as it has of everything which it contemplates, and that the mind does not enjoy them, however strained the technical expression may seem in this connection. According to this a plant has pleasure as a condition of its living body just as it has hunger and thirst ; but it is not conscious of them, for they are phases of its life and unlike us it 'enjoys' them in the extended sense of that word.
What the conditions of bodily life are which constitute pleasure and pain remains to be discovered. It by no means follows that there are pleasure-localities  (which are certainly only hypothetical), comparable to the pain-
(125)localities which are known to exist. Still less that pleasure and pain are combinations or groupings of visceral or other bodily sensations. I have been careful only to say that pleasure and pain are of the order of vital sensations. It may be that pleasure is a character of the organism in so far as any function of a sense-organ goes on in harmony with the bodily welfare ; and pain or disagreeableness correspondingly. This would make pleasure and pain a fact of " integration " as Mr. Watt supposes. But how such a life-condition of welfare or the reverse is conveyed to the conscious centre I do not know. The recent discovery by Messrs. Head and Holmes that lesions of the optic thalami intensify pleasure and pain  and also the emotions seems to imply some such arrangement for reception of pleasure and pain. All I am concerned to suggest is that pleasureableness and painfulness are not mental conditions as such but objects of them, and in themselves bodily or vital conditions of which we are conscious. If this is so, the higher pleasures like those mentioned above are greater complexities of more elementary feeling. In all probability then feeling is not a constituent of any mental act, nor a mere feeling tone of the act, but is an independent act with pleasure or pain for its object. We have thus no reason to alter the conclusion that the processes of which mind consists are the highly complex movements carrying the quality of consciousness, which are described as conations.
The one and distinctive quality of mental acts is their consciousness. What then are the contents of the mental
The contents of the mental act; empirical determinations of categorical character
(126) act or enjoyment, and in particular what is it in the mental act which corresponds to or refers to the quality of the apprehended thing or selected part of the thing, with the intensity which goes with that quality, the loudness of the sound, intensity of the pressure and the like ? When I ask what the contents of a mental process are I am using the word in the same sense as when I ask what a glass which holds water is made of and what is its shape and size and thickness. In another sense the water is the contents of the glass which holds it. But though the non-mental object is distinct from the mental apprehension of it as the water is distinct from the glass, the object is clearly not contained in the mind in this sense. Sometimes, as we have seen, the object of the mind is distinguished from the thing of which it is the partial revelation, as being the `content' of the mind. The only use of such a word is to indicate the selective action of the mind in determining its revelations of things. But it is an undesirable usage, for it is bound together with a mistaken theory and it conveys the idea that the object is still in some sense psychical. The contents of the mind' is good English for what is really in the mind, and objects are not there. What is in the mind is whatever features can be discovered in the enjoyment.
The question we are asking now is what are the mental features which correspond to the qualities and their intensities or other features which are contained in things. We are not asking for an account of the various ways in which things, with the distinctive qualities they possess on their respective levels, are apprehended, according as we merely sense or perceive or imagine or remember them or make judgments about them. All this description is the special business of psychology and does not fall to our office. Such differences in the way of our apprehension of things may be called the formal' element in the mind's operations, as distinct from the material' element, whereby the mind is aware of the character of non-mental things. It is in sensation that
(127) we meet these material features of our experience in their simplest form and we shall confine ourselves here to sensation. But the material features reappear in every form of mental activity, as e .g. when we remember a dog with its shape and colour and smell combined in a certain fashion or arrangement, or imagine a mountain of gold. Moreover, it is in the higher formal processes that it is easiest to verify the truth that all cognition is conative process, for in these we have various material elements combined, and it is easier to enjoy the process of holding these elements together in the mental transition from one to another (as for example in perception) than to be aware of the conative character of simple sensing.
The question what is the conative feature which corresponds to the material elements of our experienced world, is different from still another question, what are the kinds of mental acts by which we apprehend in turn the different orders of empirical qualities ; which will form the subject of the following chapter. At present we deal with the material side of mental life.
Now the contents of the mental act or process are those which it possesses as a process, simple or complicated. They are thus empirical determinations of categorial characters, or in other words certain empirical determinations of Space-Time. It is these spatio-temporal features which make the difference between one mental act and another according to the object it apprehends. The sensing of green differs not from that of blue in quality, for sensings have no quality but consciousness, and the so-called quality of the sensing is really the quality of the non-mental sensum, blue or green or sweet. It is thus some empirical determination of a categorial feature of the mental process which is enjoyed differently according to the quality of the sensum. It is some determination of enjoyed space-time. In a previous chapter I said that according to the character of the object we are vaguely aware of a difference in place and time and more particularly in enjoyed space
(128) (for we are obviously aware of the occurrence and duration of our mental acts in time). These vague deliverances are supplemented by reference to the contemplated space of the brain where we have reason to believe that our mental processes are located. We may say then that we enjoy our acts of sensing, as they vary with the quality of the sensum, as the direction of our enjoyment in mental Space-Time, and this direction is identical with the locality and direction of the underlying neural process. Such a description is open to the quite intelligible misapprehension that the process is supposed to be in some manner directed upon the sensed object, whereas direction of the mental process means the actual movement within the neural space which is enjoyed as direction in the identical mental space. It is possible, however, to explain the situation without the misleading word direction, but employing the same thought.
The spatio-temporal mental correlate of the quality of sensation. Problem II
Necessarily any exacter answer to the question must at present be largely a matter of speculation or hypothesis. But it has been suggested by Mr. C. S. Myers in an important paper that the so-called quality of the sensation depends on the type or pattern of the neural reaction to the quality of the stimulus. I adopt the word ' pattern ' or 'type of neural reaction ' as a less vague and more accurate alternative for its direction.' In my interpretation the meaning of the two descriptions is the same, but I hasten to add that in adopting Mr. Myers's hypothesis I do not father on him the view that there is no quality in sensation or that the object has a quality irrespective of the mind.
I am assuming that the neural reaction or response includes the whole process of afferent, central, and motor parts, and that it is not possible to correlate sensation solely with the afferent part of a sensory reaction to a stimulus. The neural correlate of a mental process is (as I believe, with my insufficient instruction, to be good physiological doctrine), not separable into parts but a whole. Indeed I gather that in Mr. Myers's view it is of the two rather the movement or behaviour of the living being which is the essential feature of the reactive type. The mental act then, I assume, corresponds to the transition along the whole arrangement, as that transition proceeds from afferent to efferent tracts. Perhaps it is the juncture between the two which is of chief importance, for it is there that the motion along one set of nervous elements is switched off into the other. Mr. McDougall has indeed put forward the well-known hypothesis that consciousness is situated at the synapsis or juncture between neurones, and with this the above statement is consistent. Thus the type or pattern of reaction would be the physiological plan of connection between incoming and outgoing process. Supposing this to be correct, the mind in the act of sensing enjoys in the space-time of the mind this configuration of movement, which issues in certain physical movements of the limbs or other organs, and the difference in acts of sensing according to the quality of the object sensed is not a difference in any quality of the mind, but in this empirical character of the place and time of the act. The enjoyed categorial determination in its empirical form is identical with the contemplated pattern of reaction which the physiologist can observe or suppose. And this result appears to me to be merely a more accurate statement of what we can very roughly discover
(130)in our enjoyment by simple inspection of more complicated acts of mind.
This enjoyed spatio-temporal pattern or direction of sensing I shall speak of as the intrinsic extension' of a sense-process (both in space and time) in order to distinguish it from the extension or extent of sensation which we experience when a sensation is prolonged in duration or when we experience a mass or group of like sensations. The alleged extensity ' of sensation, or its voluminousness is, we shall find, a character which attends a number of sensations, but is not intrinsic to them but to the space they occupy. The protensity ' of sensation is nothing but its continuance, that is, again, a continuous repetition of the sensation in time. Any act of sense has its place in mental time and space ; but what determines its empirical difference from other sensings is more particularly the enjoyment of the spatiotemporal pattern or direction. The sensing may be momentary or prolonged. But even so far as it is relatively momentary, it still has its pattern which is the intrinsic extension.
How, it may be asked, if sensing is a spatio-temporal pattern, can it be enjoyed otherwise than as an extent ? Even if it exists but for a moment, does it not occupy its pattern and is not this an extension and spread out, if only in lines and not in area or volume ? The answer takes us back to the more elementary and fundamental considerations of a previous portion of this work. The pattern is not spatial merely but spatio-temporal, and its neural basis is not merely anatomical but physiological. The consciousness of sensing does not at any moment fill the whole neural structure of afferent, central, and efferent parts. Let us suppose that a sensing is purely momentary, which it never really is. It occurs then at some point-instant (or group of such) ; let us think of the point-instant at which the afferent process passes over into the efferent one. But that point-instant has a past and a future. It lies on a line of advance or it is the point at which complex lines of advance are continued into another complex. It is the pattern of the sensory
(131) process which determines where the past and the future of the process are. The present moment of sensation is the point-instant where the direction of the future is determined by the past. Thus that moment of sensation sums up or integrates ' the character of the whole pattern. The difficulty arises as said from thinking of the pattern as merely a geometrical one ; it is in fact a plan of motion. The intrinsic plan of reaction which gives the sensing its determinate character is therefore not to be conceived as a stationary plan like an architect's ; it is a scheme of transition, and hence in this respect the idea of direction ' not only cannot be dispensed with in supplement to that of pattern ' but is in fact the more expressive designation. The locality of the sensory act is included along with its direction or pattern, for certain patterns of reaction occur in determinate places in the neural structure. The distinction between the intrinsic space-time of a sensation (i.e. a sensing) and its extent will occupy us more largely in the following chapter. It corresponds to that between the quality of blue which belongs to any point whatever in a blue patch irrespective of its position, and the whole extent over which that quality is spread. We have extent as distinguished from intrinsic extension or direction wherever we have many processes going on in the mind at once, whether they are homogeneous, as in the vision of a coloured patch, or heterogeneous, as in any complex apprehension like perception or imagination corresponding to an object of complex qualities variously arranged.
The universal element in sensation
The pattern of configuration in any existent we have seen to be its universal. In any sensory process (or in any other mental process) there are the categorial feature of existence as a particular and the categorial feature of subsistence, or existence as a universal. The same distinction is found in the object or sensum. As to sensing, its particularity depends on the particular time of its occurrence and its particular locality within the large sensory neural region devoted to that species of sensing,
(132) e.g. within the occipital area of vision ; on variations of intensity ; and on any variations of whatever kind which leave the pattern unaltered. Psychologically this means that any sensing process is one of a certain kind and its object one of a certain universal quality. From the beginning of psychical life the universal and particular are united ; and this is a recognised commonplace of the subject, and is illustrated at any length in the charming transference which children make of words learned in connection with some particular object to any object which is reasonably like it in kind. In other words, though sensing is not thinking there is no sensation without its universal or thought. What thinking does is merely, as in conceiving, to contemplate the universal in the object, by itself; and detach it from its particular surroundings as a separate object of attention. Thinking is the corresponding mental act which apprehends the universal as such, and we have already verified the existence in consciousness of the distinct awareness in enjoyment of the plan of any complex. When we think a colour, e.g. blue, we in like manner enjoy the pattern of blue, which is intrinsically a spatio-temporal complex, however simple. Thus thinking is only one of the formal varieties of mental process, it adds no question in respect of the material side of the mental action, except the question whether thinking possesses also intensity, which is another material feature of sensing.
Intensity of sensing
We have now to ask what spatio - temporal or categorial character is enjoyed as the intensity of the sensing, in correspondence with the contemplated intensity of the stimulus. The answer is still more speculative than that we have just given to the question what corresponds in the sensing to the quality of the sensum. Mr. Myers suggests as the ground of variation in intensity of sensing the number of the nerve fibres,
(133) afferent and efferent, which are called into play in response to the intensity of the stimulus, so long as the type of reaction remains unaltered. It is the moreness or lessness of a reaction of the same type. While the quality of the sensation depends on the pattern of the reaction, the intensity depends on the extent of the lines of the pattern. Another physiological hypothesis put forward by H. Munsterberg regards the intensity as due to the quantity of excitement of the nerve fibre, or fibres, supposed to be the afferent ones. This implies that as is commonly believed a fibre can respond more or less to different degrees of stimulation. I imagine that greater excitement within a fibre would mean a larger use of nervous elements, the greater stimulus breaking down elements which resist the lesser stimulus. The other hypothesis is based on the view that the response of a fibre does not vary with the amount of stimulation, but is of the all or none' kind, that is, the fibre either responds uniformly and completely or not at all. This question is one for physiologists to settle. Mere reference to the number of fibres involved, while simpler, presents obvious difficulties, for it would seem to imply a discontinuous scale of intensities of sensation ; and whether this is so or not is one of the vexed and very difficult questions of psychology. A purely psychological hypothesis had already been propounded by Prof. Franz Brentano, that sensory intensity is the measure of the 'density' of the sensation (that is the sensation on its objective side) in what he calls the space of sensation (Sinnes- or Empfindungsraum). That is, he imagines the sensation (I must not call it the sensum, for that carries with it the implications of my own view, but I may use the non-committal word sense-datum) to be stippled over the sense-space, leaving gaps, and the denser the stippling the intenser the sense-datum. On the subjective side
(134) there is correspondingly more or less of the sensing, positive sensing mixed up with privations of it. The intensity is in either case the ratio of the full and void, and obviously the intensity is precisely the same on both sides. We may adapt the idea of density thus propounded and give a spatio-temporal interpretation not merely to the intensity of the object but to that of the sensing, falling back on the more physiological aspect of sensing. The spirit of the hypothesis is the same as that of the physiological ones I have described. For on the view of Mr. Myers the maximum available extent of the pattern is occupied more or less densely and the idea applies obviously to Munsterberg's doctrine.
But in using the notion of density whether in the physiological form or not, a proviso must be made. Density, being a ratio, is enjoyed in the mind (or contemplated in the object) not as an extensive quantity or as merely a matter of number, but as an intensive quantity. In accordance with the abstract description of the category of intensity given in a previous chapter, the intenser sensing occupies a greater space in the same time. But the space-time so occupied is enjoyed together and as a whole. It may be resolved into numerical parts, but this is something true about it and not what we are acquainted with. We are not to suppose (taking Mr. Myers's hypothesis) that the difference between one intensity and another is the mere addition of the n+ ith fibre to the n fibres of the less intensity, as if it were merely a matter of adding another unit. For the n + ith fibre only comes into play when the n fibres are already used. In other words we cannot suppose that this n+ ith fibre, call it fibre x, might indifferently have been one of the n fibres which made up the lower intensity. We must suppose that within the available maximum extent of the nerve, the fibres are called into action in a certain order according to the intensity of the stimulus. In the same way when fresh doses of manure are added
(135) to land we cannot say merely that more bits of the soil come to be fertile, as if the fertility depended on numerical addition of bit to bit, though it can be so expressed. The last bit of production by the soil is only brought into play through the last dose of manure and is therefore not as it were a unit which might have occurred indifferently anywhere in the process of reaching this stage of productiveness. Fertilities form a scale each member of which is a unitary whole, and the unit in such a scale is the unlikeness of one member of the scale to the next higher fertility. Only indirectly by correlation with the amounts of manure can the scale of fertilities be measured by units in the strict sense, as a line is composed of inches all exactly alike. Similarly, though the intensity of the sensing may be resolved into or correlated with greater or less number of the conscious excitements in the sensing, it is not the mere numerical difference which makes the greater intensity, for the numerical difference must according to Weber's law be at a certain rate or ratio in order to produce differences of number that are appreciated as differences of intensity. In other words, the numerical or extensive formulation of the intensity is but the extensive equivalent of the intensity. Thus the brightnesses in the illumination from a number of candles may be represented as depending on the density of illumination by separate candles, but that density is experienced not as an addition of units but as a whole. Each member of the scale is an individual, not resoluble in the intensive experience into units ; though so expressible. We do not enjoy the supposed neural stippling as a number but as intensity.
Has thinking intensity?
Sensation, we saw, whether the sensing or the sensum, contained a universal as well as a particular, the universal being the grouping of its elements, or the plan of their construction. The higher mental acts up to thinking are more complex groupings of sensory or ideational elements and involve universal plans. Now, it is clear that think-
(136) -ing being the explicit consciousness of the universal whether taken by itself as in bare conception or (as in fact it always does occur except by an abstraction) as a component element of judging or inference, is the consciousness of a plan and is itself a plan of mental action and has in this sense a kind corresponding to the kind of the universal in the object. The thinking process whose object is dog is different in kind (though not in quality) from the thinking of cat or house. But does thinking possess intensity ? Mr. Brentano in the same chapter answers unhesitatingly no, for there is no possible variation of density in either the thought or the act of thinking. The answer is clearly correct so far as we have pure thinking or pure thought or a universal. A plan of grouping has no intensity ; as we have seen, the category of universality does not communicate with that of intensity. But the plan is such as to admit intensity in the particular or individual cases of the universal ; it includes intensity but has none. The same thing is seen to be true of the thinking. It is the consciousness of a custom of mind or disposition, and a custom has not intensity, though it may be more or less lively in the sense that the mind may possess a greater or less readiness to act along the line of certain customs, a greater susceptibility or suggestibility in respect of them than of other customs. The object of such custom is the imageless thought or universal.
Still at the same time thinking is a particular mental act and can no more exist without some particularity than a sensation without its universal. Some point d'appui is needed for our thinking. It may be and perhaps most commonly is a word ; it may be a particular illustration of the thought in perception or image ; it may be some heterogeneous percept or image. Intensity belongs to the thinking in so far as it is clothed in particular circumstance, and it never can dispense therewith in fact. But this intensity is not intensity of the custom. There is a custom which allows for intensity in its elements, but no intensity of the custom. Only, just so far as the particular circumstances to which the custom is attached are faint or
(137) intense must the thinking have the intensity which appertains to them. Hence in an imageless thought any part of the thought may at any moment take on the particularity of an illustration. It may, if I may judge from my own case, be difficult to prevent it from straying out of the imageless region of thought, and then it becomes endowed with intensity. Plans of mental action are in fact the transitions from element to element, and though transitions may be swift or slow, lively or dull, that is not a feature of the transition itself in so far as it is the consciousness of the grouping which is the universal. Apart, then, from the intensity which belongs to thinking indirectly as related to some particular, thinking has not intensity. The intensity of thinking, which as we have seen is speculative willing, is either a name for the effort of attention which it involves and which arises from its particularising circumstances and which largely also consists in bodily experiences of a sensory character ; or it attaches to belief, with its emotional character, which may vary from languid acceptance to intense ' conviction. Thinking is in fact on the same footing as sensing. In sensing it is the particular with its intensity which is salient and the universal in it is not detached. In thinking the universal is detached but it still remains attached to some particular and thereby has intensity.
So much then by way of suggestion towards a more exact description in terms of space and time of the kind and intensity of sensing. These are its material contents, its pattern and its density. All its other contents are equally spatio-temporal, and have no quality but that of being conscious and so enjoyed. Of its so - called `extensity' and localisation more remains to be said in the following chapter ; but these and its duration and date plainly belong to its space and time. A sensation has other categorial features : it is a substance, stands in relation to other sensations, etc. In particular it has order, and we have noted the application of the idea of order to the various qualities within any modality of sense,
(138) like the pitches of tones. As for the liveliness or obtrusiveness (Eindringlichkeit) or impressional intensity, as Mr. Stout calls what Hume described as vivacity, it appears to me at present to be of the formal rather than the material order of characters of sensing ; and the other categorial features of relation, substance, and the like, call for no remark. And since the higher mental acts of perception, etc., are but groupings of simple elements of sensory or ideational kind in a spatio-temporal plan, we have the result that the only contents of mental acts of whatever kind are empirical determinations of purely categorial characters, and have no quality but that of being conscious and enjoyed as such. Above all, the object of consciousness is in no real sense the so-called 'content' of it.
Secondary qualities and the mind
Here appears to be the place for reverting to a deferred problem, and defending the thesis that secondary qualities do not owe their character to the mind, but only owe to it the fact that they are seen or tasted. It is difficult enough, in consequence of philosophical tradition, to maintain the position that colour or heat reside in the external things themselves, when the necessary physical conditions are fulfilled, such as the presence of light ; and the position is still more difficult when the proposition is extended from colour or heat to taste or smell. But at least to think of a material process carrying the quality of colour is no harder than to think of a neural process as carrying the quality of mind—facts which we have to note and accept as the way of the world—or than it is to think that in hunger we are sensing a bodily or vital process called depletion. We are so apt to think that in this last case the mind is in a manner hungry, whereas the mind is only aware of a vital condition called hunger.
But now that we have attempted, however hypothetically, to identify what the process of sensing a quality is as in the mind, and find it to be a pattern or type of response enjoyed by the mind as direction, which varies with each type of quality sensed, the theoretical difficulty
(139) belongs rather to the philosophical theory that colour or taste owe their being to the mind. This theory, while it has no support in unsophisticated thought which does not ask such questions, receives no support either from physics or physiology, which deal with the facts of sensation, the one by inquiring into its physical conditions and the other its neural conditions, but do not concern themselves further. Indeed it may be supposed that the notion would never have arisen had it not been in the first place for the difference between qualities proper and the primary characters or qualities ' of matter ; and secondly, for the interpretation of images as the work of mind. If it is true that the image of a red rose is mental, then since it includes the colour red, that colour is mental as well, and may be equally mental when it is perceived. But when the imagining is distinguished from the image, and when further we can say what corresponds in the imagining to the quality of redness, the notion that the colour is in any sense a creation of the mind in its co - operation with physical movements proceeding from the external rose ceases to be even plausible. There is in fact something unintelligible in the idea that out of heterogeneous material the mind could fabricate a colour or taste or smell. The only thing which makes such a notion plausible is the variability of the sensible qualities of things as the conditions vary which affect the perceiving mind : the disappearance of taste or smell with a cold in the head, the confusions of the colour-blind, the purple of the hills at a great distance ; matters which await discussion in a subsequent chapter (ch. vii.).
Secondary qualities and the sense-organs
But when we have abandoned this conception, a more insidious one sometimes takes its place. The mind indeed, it is said, does not create colour, but colour owes its existence to the physiological organism ; it does not depend on the mind but upon the eye. In what precise sense this is understood has not been definitely explained, and two alternative interpretations are possible. On the one interpretation, colour is an affection of the eye which
(140) the mind apprehends ; on the other, it is a product of the action of the eye on the light, comparable to the peptones produced by the action of the gastric juices on food, or the uric acid secreted by the kidneys as the blood is strained through them, or the carbonic acid generated in the air of the lungs. In neither of these ways can secondary qualities be held to depend on the bodily organism.
On the first alternative, which has probably not been consciously entertained, colour is an affection of the body, and in particular of the eye, which the mind apprehends as it apprehends depletion as hunger, so that in vision the eye, to adopt a convenient Aristotelian phrase, is in a manner coloured. All the sense qualities then would be of the same order as hunger and thirst. But these are felt in the body and localised in the same place where we learn to localise the stomach or throat, and consequently we feel them in the stomach or throat ; whereas colours and smells are not localised in our bodies but in coloured and fragrant things. Our plain experience is that we do not see colours in our eyes, but only with our eyes and in the rose or apple. Further, if we are aware of colour as an affection of the body, why is it more difficult to suppose that we see it in the rose ? It will not do to say that chemical effects produced in certain substances in the eye are sensed as red though not red in themselves. For then we revert to the notion that it is the mind which apprehends as red what is not red at all.
The alternative analogy of the colours and tastes of things with the products of vital processes, such as digestion and respiration, is open to even greater objections. In the first place it also assumes that the mind is a passive spectator of the results of the interaction between the body and the external thing, and like the first alternative fails to account for the localisation of the sensible datum in the external thing. Moreover, it would appear to exclude from the physiological participants in the interaction between organ and stimulus the neural process itself. For if it is true that the mental and the
(141) neural process of sensation are identical, if the mind does not participate, neither can the neural process. What participates must be the non-neural processes in the organ ; for example, the action in the rods and cones before the neural elements of the retina are excited. The bodily organ which enters into the transaction which creates colour is comparable therefore to the blue spectacles which are not themselves seen but colour the world blue. But the comparison breaks down. For the blue spectacles do not account for the world's appearing coloured, but only for its having the blue tinge. The spectacles being coloured add their colour to things which already have colour ; much as the intervening air makes the mountain look purple. The supposition is therefore irrelevant ; and it leads also to the strange conclusion that eyes which are adapted for seeing things serve only to distort their true characters.
This leads us to what is the fundamental difficulty in the notion. It supposes that out of physico-chemical substances, the external thing and the bodily organ, life can create a new quality of colour which is not itself physico-chemical. Whereas for experience life reacts on such substances and produces substances higher or lower in structure but chemical substances still ; it may transform their colours if colours already exist, but it does not create a new thing, colour. This objection is fatal if the theory meant merely that the colour of a thing is a quality which it receives in the course of living reaction upon it. I am inclined, however, to think that in treating colour as dependent on life in a way in which it is not dependent on mind, there is lurking a notion that the creation of such products is the business of life, while it is not the business of mind ; that life consists in such production while mind does not. In truth, life is a set of processes, of breathing, digestion, and the like, whereby ingested material is transformed into excreted material, and the organism regulates the production of these changes with supreme delicacy. But these transformations are only changes of material substances into other material substances ; life does not consist in these
(142) transformations, which are the incidental results of life. It consists in the bodily movements or processes by which they are brought about. Life does not reside in the air which the body takes up and breathes, but in the actions of its parts by which the composition of the air is affected. But, so understood, cleared from the misconception that the living body is a machinery for transforming matter from one shape into another, life is in all respects parallel with mind, and the production of secondary qualities by mind no more difficult to understand than their production by life, and no advantage is gained by the substitution of the physiological organism for mind. In fact, the modification of ingested substances by the body has its exact parallel in mind in the process by which the mind adds to the objects which are presented to it in sense ideas, that is ideal objects, corresponding to acts of imagination or reproduction. In neither case is something new created which is of a different rank from the subject-matter which either life or mind operates upon.
We are compelled then to deny that either mind or the living sense organs give to secondary qualities their being, and to affirm that these reside in the material things themselves. We have to accept the fact that besides the categorial element in things there is also the strictly empirical element of quality of which the secondary qualities of matter are an example. At the same time these two elements are not disconnected, for quality is carried by particular complexities of the a priori foundation of all things, Space-Time, whose fundamental features the categories are. Miraculous we may call the existence of quality if we choose. But it is at least a miracle which pervades the world of things. The relation of the secondary qualities to matter is not stranger than the relation of life or mind to that which carries them. On the other hand, to attribute the secondary qualities to the work of mind is to believe in a miracle which is unique and does not conform to the ways of things.