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Lecture VIII. Vision and Contact

Lecture VIII. Vision and Contact
XXXVI. Projicience in Vision. XXXVII. Contact. XXXVIII. The Property of Beauty. XXXIX. The Property of Colour. XL. “The Bifurcation of Nature.”
§ XXXVI. Projicience in Vision.

“Two places of different sorts” says Mr. Bertrand Russell “are associated with every sense-datum namely the place at which it is and the place from which it is perceived” (M. L. p. 158). For this I should substitute: The assigned place at which it is and the place of location to which it is referred (cf. p. 53).

Let us start with visual acquaintance. One sees a green lamp-shade out there. Two systems are here (on our view) in extrinsic relatedness. The lamp-shade qua acknowledged thing is one; a person is the other. May we say for the purpose in hand that the lamp-shade is at the place from which there proceeds a physically effluent event or set of events: that what reaches the person's retina is an influent event; and that the retina as recipient record is the place at which there is a receptorevent? Then what the receptor-event is directly due to under acknowledgment is the influent event.
This receptor-event is to be regarded on the plane of matter as physico-chemical. As such on this plane it is closely analogous to that which occurs in a photographic record. It is emergently at a higher level than that of the electro-magnetic influence which evokes it; and as record it affords the first step upwards towards vision in the person. In the person the receptor-event happens and beyond the confines of the person it has no being. Since it is that which is involved in sensation it is that which the biologist must regard as the “sensedatum” or “sensum” if he should elect to retain the use of this ambiguous word. Hence the difference between Mr. Russell's statement and mine.
Thus far I tell in brief a purely physical story of the events involved in vision. This first chapter of a very complex bit of evolutionary history brings us up to a very highly specialised kind of receptors to which Sir Charles Sherrington has given the name “distance-receptors.” The name implies that under physical interpretation there is a space-interval between the place of the effluent event and the place of the receptor-event to which influence is transmitted with the velocity of light and since this velocity is finite there is also a time-interval between effluent departure and influent arrival. If we call the centre from which the effluent event proceeds the source of influence the points for emphasis are these:
(i) What the distance-receptors are immediately up against is the influence that arrives;
(ii) They are only mediately in relation to the effluent source from which such influence has departed some time ago however brief
(iii) That to which the behaviour of the person is directed is the source from which the influence comes; and
(iv) If conscious reference is to have any value for such behaviour it must be directed to that source.
Under (iii) we pass to the biological chapter in the story of events. One can only indicate here its salient motif. It seems pretty well established that the physiological outcome of the stimulation of any group of distance-receptors (which will include those for radiant influence for sound and for odorous particles—each after its kind) may become linked with any adaptive response which has value for behaviour towards the effluent source. Such neuronic linkage has been provided in the course of long ages of evolution. In vertebrates it has reached its highest level in the central nervous system and finds expression in the integrative action of the brain. “The brain” says Sir Charles Sherrington with the emphasis of italics “is always the part of the nervous system which is constructed and evolved upon the distance-receptor organs” (I. N. S. p. 325). So far the interpretation may be frankly behaviouristic for biologically the brain is par excellence the organ of the guidance of behaviour.
But according to emergent evolution vision while it requires the integrative action of the brain is also on the plane of mind. Something happens in the distance-receptors under light-influence; given these receptor-events on the plane of life there arise in the person “possessed of” a brain presentations (or “sense-data” as we should use the word) which acquire in the course of experience objective reference centred on things at a distance. “Projicience refers them without elaboration by any reasoned mental process to directions and distances in the environment fairly corresponding with the r‘real’ directions and distances of their actual sources” (I. N. S. p. 324).
I follow Sir Charles Sherrington in the use of the word “projicience” seeking thereby to label a salient feature in the interpretation I have to develop but be it clearly understood without any thought of implicating him in such heresy as may attach to my evolutionary creed (cf. § VIII.).
My aim is to distinguish:
(1) Adenience of physical influence on the plane of matter from
(2) Projicience which obtains only on the plane of mind.
But between the one and the other there are multifarious occurrences in the brain and elsewhere on the plane of life. I speak of these under the heading:
(3) Intervenience of organic or vital events.
The position then is that advenient physical influence calls forth in the organism a very complex system of intervenient events with psychical correlates; that these events culminate in behaviour towards the source from which the advenient influence was effluent; and that projicient reference endows the thing with all the meaning that accrues under correlation as the net result of all intervenient events thus rendering the acknowledged thing an object of perception which for our reflective thought is always in some measure conceptualised (cf. § VII.). Apart however from the added embroidery of reflective contemplation (Sir Charles Sherrington's “elaboration by any reasoned mental process”) it should be realised that visual projicience which to the plain man seems so transparently simple a matter is prodigiously complex. And why? Because from the standpoint of evolution the intervenient events involved on the plane of life form so intricate a nexus. We cannot here pause to unravel the threads. This gives one of the central problems which fall for consideration under any adequate discussion of the nature of the correlation of behaviour with all that it involves and consciousness at the perceptual level. One looks out on a landscape. All is so neatly and simply ordered for vision. But ask what is intervenient in the organism between this projicience apparently so simple and the physical influence which is advenient. In binocular vision there are two “inverted” receptor patterns with “correspondence” and “disparation” (crossed and uncrossed) in the technical sense of these words; there is the factor of convergence; that of the movements of the eyes in their sockets with changes of “local signs”; in each eye there is the factor of lens-accommodation; there are all the secondary or “associative” conditions which facilitate location of objects; there are all the varied contributions under revival in terms of other experience than that which is visual e.g. those which are derivative from manipulation through touch perhaps contributions re-presentative of smelling tasting and so forth. All these are intervenient in the organism and through this intervenience involved on the plane of life make projicient reference under correlation what it is on the perceptual plane of mind. It is in virtue of all this that Sir Charles Sherrington speaks of the brain as “evolved upon the distance-receptors.” To ignore all this would betray sheer ignorance of the topic one pretends to deal with. Is it not set forth in the text-books (cf. Stout M. Bk. III. Pt. ii. ch. 4)? In any case so much of all this as is pertinent must be taken as implied when I speak of projicience.
Projicient reference on the plane of mind thus affords the subject-matter of the third chapter of the complex story I briefly summarise. How comes it that it works so wonderfully well as a guide to behaviour? To this question evolutionists seek to give an answer based on prolonged research. The net result seems to be: Because it has been endorsed by the survival of those organisms in which so serviceable a process obtained.
It follows that there is: (i) the assigned place of effluent events; there is (ii) the assigned place of receptor-events under influence; and there is (iii) the located place of projicient reference which may and often does approximately coincide with the assigned place of effluent events but need not do so and frequently does not (cf. § VIII.). Let it then be understood that vision is always an affair of distance-receptors and that everything we see is subject to projicient reference. I shall urge that visible shape or size does not afford the best avenue of approach towards the acknowledgment of the intrinsic reality of this or that shape or size.
One need not repeat in detail the oft-told story of the coin with manifold variations of apparent figure and bulk from different points of view and at different distances. Each such appearance without exception is a matter of projicient reference subject to the conditions of extrinsic relatedness which then and there obtain. They are properties of the coin which no doubt may be clues to the intrinsic qualities which we acknowledge as its own (cf. § XXXIII.).
Now it would conduce not a little to the analytic interpretation of the facts if we could (at any rate initially and provisionally) wipe mind and its projicient reference off the slate. Let us try to do this and to deal only with what occurs in the recipient organism—Mr. Whitehead's “percipient event” (C. N. p. 152). We grant to the thing under acknowledgment its own intrinsic shape. There are two systems in extrinsic relation (i) the said thing with its proper figure and (ii) some other thing in which a record is produced through influent events effluent from (i) as their source. In the organism such a record is a pattern (the so-called “image”) on the retina; and the pattern thus recorded is itself a figure correspondent to that of which it is a record. But the recording system need not be the retina of a person; it may be some other recipient such as a sensitised photographic plate which gives what I shall call an optical record. In this case the terms in extrinsic relation—figure of thing and recorded figure—are both frankly spatial systems with comparable relations of the spatial order. Given then on a film successive snapshots of a coin rotating on a selected axis and one has an optical record giving figures closely comparable to the “images” on the retina at similar intervals.
Reintroduce now the conscious percipience which we have banished for awhile. What happens? Under projicience the proper figure of the retinal “image” or of the record in the film is referred to the coin as a direct or indirect object of vision. Qua object it extrinsically acquires the perspective property of the shape projicient from the record. But of the intrinsic figure of the coin (let us say) vision as such can give no assurance—only a clue to be elsewise followed up. Not along the lines of projicience (the only lines open to vision) can intrinsic reality be reached. The world of vision is always a world of appearance—objectively real in extrinsic relatedness but affording no voucher for intrinsic reality though it may give a clue thereto.
We have then as distinguishable (a) projicient or apparent shape subject always to “point of view” and (b) intrinsically real figure under acknowledgment. And the projicient shape may differ from or in some cases it may accord with or correspond to the intrinsic figure proper to the coin. The correspondence if it obtain is that between figure of coin and figure in record (retinal or optical) both circular but always differing in size owing to the part which is played by the lens.
§ XXXVII. Contact.
The argument thus far is that projicient vision affords a valuable clue to the intrinsic spatial relatedness which obtains within the thing that I see out there; but that it is incapable as such of affording more than a clue to the determination of what the spatial relatedness is in and for itself. What then does afford under acknowledgment something more than a clue? I think that the old answer is still that which can establish the best claim to acceptance. It comes in effect to this. We must build on a basis of contact-receptors which is the primary basis of measurement.
Let it be admitted that the spatial characters of some given system other than myself—say that of the room in which I sit or that of the cube on my desk—is for our reflective knowledge a construct to which suitable data are contributory. I urge that the suitable data are derivative from contact. I say “contact” because I wish here to abstract from manipulative touch which implies much intervenient process.
Consider the glass cube. Any two minute areas of its surface which I choose to mark with ink-spots afford spatial terms in the spatial relation of distance within the confines of the cube. As a relation this distance is indivisible; but it may be co-related with a measured stretch or length on some con—ventional scale (cf. § XII.). Hence one may substitute for any indivisible distance-relation its co-related scale-length. There are an indefinite number of such instances of spatial relatedness within the cube. We deal with them methodically in the light of what we have learnt through manipulation under the guidance of reflective thought. Only then have we the analytic data on which to frame a synthetic construct. One may assume that we have long ago done something of this sort in such manner as to understand what is meant by saying that we are dealing with that which we agree to call a cube.
Now primarily and fundamentally all direct measurement of the kind we are considering is based on superposition under contact. By means of suitable instruments—calipers rods and the like—two terms in one system are within narrow limits at the same assigned places as two terms in the other system and their distance-relation is under acknowledgment the selfsame distance. What seems to be essential is that under such terminal contact the analytic data obtained by measurements of the recording system and of the system recorded are one and the same. This is never so where the distance-receptors of vision on the hither side of the lens play their normal part as record. Under contact each of two systems may be regarded as reciprocally functioning as record to the other. In vision there is no such contact.
Let me put the matter thus. I superpose a suitable surface of my body on a suitable surface of not-me in contact therewith. I consider the end-points in contact. I regard these end-points in me and in it as substantially coincident—i.e. as lying within a small area; and I regard the spatial distance “between them” i.e. their spatial relation as substantially the same under acknowledgment. I then superpose the second “length or stretch” derivative from spatial relatedness intrinsic to me on some third surface say the wall of my room. And I accept the supposal which seems to have pragmatic sanction as a basis of measurement that the length a−b intrinsic to me the length a'−b' intrinsic to the “foot-rule” and the lengthα−β intrinsic to the wall to which I apply this foot-rule are qua length what we may call one and the same or if it be preferred equivalent. Thus I can “install” as I put it a little bit of my intrinsic spatial relatedness in the little bit of intrinsic relatedness which belongs of right to the wall of my room. It is a piecemeal business. That's where the construct comes in.
One must not minimise in all this the guiding value of projicient reference under vision. That would be to ignore not only patent facts but the pragmatic “end” which distance-receptors subserve in evolution. I sit in my room and scan the ceiling floor and four-square walls as seen in perspective. It may be that here and now I employ no contact-treatment. I do not through manipulation actually bring some selected bit of my intrinsic relatedness through the intervention of a foot-rule into touch with any selected bit of its intrinsic relatedness. But I can do so on occasion. And I can here and now do so imaginatively. That is where the projicient experience of vision comes so helpfully to my aid. I can so to speak throw a little bit of my physical self or my foot-rule on to this that or the other selected instance of intrinsic relatedness within the room. With the aid of the clues afforded by vision I can bring it imaginatively within the field of contact. But can one not do more than this? Can one not by a further and more resolute effort install oneself in the total spatial relatedness intrinsic to that which one reflectively contemplates? Can one not imaginatively expand or contract oneself and fit oneself as record to the thing room cube or what not—so as to be pro hoc one with its total system of intrinsic spatial relatedness? I have been told by an architect (when he grasped my uncouth phraseology) that this is just what those in his profession who are worth their salt do as a matter of course. “One must somehow” he said “get at the building as it is and not merely as it will look from this or that point of view—important as that of course is.” I believe that it is by imaginative processes of this sort that the worthy man of science dealing with his special province succeeds in interpretation where the hodmen of his trade fail. I well remember how years ago a physicist of note from whom I sought help in certain questions of double refraction said: “You will never get the matter quite clear till you can sit inside a crystal so as to feel the course of the rays of light as they pass through you.”
The upshot then comes to this. Our knowledge of the shapes and sizes of external things is no less a constructive product than our knowledge of such properties as colour or scent which we attribute to such things. But on the basis of con tact-treatment we seem justified in believing or as I say acknowledging as part of our evolutionary creed that so far as spatial relatedness is concerned what a thing is known as under contact that it veritably is. The figure and bulk of a given quartz-crystal is I believe intrinsic to that thing and is nowise dependent on its extrinsic relatedness to some percipient person.
I am doubtful however whether even through the avenue of approach afforded by contact-data the intrinsic spatial relatedness within the crystal is susceptible of irrefragable proof. After all it may be said you are dealing with “appearances” to the sense of touch; you have insisted with frequent reiteration that all such appearances as minded are within the mind-no doubt as you put it objectively; a tango-receptor-pattern on contact no less than a distance-receptor-pattern in vision is something that has place in the organism and not beyond its confines; and yet you speak of a belief in the intrinsic nature of that which confessedly lies beyond those confines; you may have narrowed the gap but you still have the “fatal leap” from what you call person to thing. Furthermore you admit that the real shape of a thing as we come to know it is a construct; you speak of imaginatively “installing” yourself (i.e. the intrinsic order of spatial relatedness involved in your own bodily structure) in the cube or the room; and so forth. Here you emphasise the necessity of taking your fatal leap.
It is just because I grant all this-nay more because I urge its validity-that I must still speak of acknowledgment. So I put the position which I am concerned to put as clearly as I can in summary fashion thus: (1) It looks very much as if this line of approach leads me towards intrinsic reality in things external to me; (2) I shall take the risk of acknowledging this to be a feature of the physical world as it veritably is.
§ XXXVIII. The Property of Beauty.
In the foregoing section there is at least an approximation to a frankly realistic view of spatial relatedness as specifically intrinsic to this or that thing in an external world. It is no doubt true that under the conditions of projicient vision many things thus appear to which the application of direct contact-measurement is impossible. Take for example the rainbow which in § XXXI. stood for our world. We cannot apply calipers or foot-rule to measure its breadth. None the less we may acknowledge that it has its own real or intrinsic breadth i.e. the distance between some rain-drop rays from which stimulate the cones on the upper edge of the retinal pattern and some other rain-drop rays from which stimulate the nether edge of that pattern. By indirect means this distance can be measured or co-related with a measured length; and on the basis of data derived from contact-treatment one may infer spatial relations which are not directly susceptible of contact-measurement by superposition.
Now we distinguished not only the form but the colour and the beauty of our rainbow. Can the beauty and the colour be interpreted realistically on lines similar to those of our interpretation of form or shape? Are the beauty and the colour intrinsic qualities of the bow or are they properties acquired through extrinsic relatedness to some person? Divergent answers are given to the question thus differently expressed. Let us lead up to colour through beauty considered only in the light of this question.
That which has beauty thereby possesses value for aesthetic treatment. Professor John Laird as representing a philosophy of realism contends that this beauty is valuable in itself whether any personal mind appreciate it or not. Let us then take it as our chosen example of value. Mr. Laird says: “A romantic revival may be needed to reveal the stateliness of Gothic cathedrals or the serene grandeur of Alpine summits but this beauty and the worth of it belonged to the Alps and the sanctuaries all the time” (S. R. p. 126). Delight no doubt enters into the recognition of all beauty; and things may certainly be beautiful when they bring this delight. But “the beauty (and therefore the value) of these delightful things is a predicate of them just as certainly as their lustre is a predicate of my lady's diamonds” (p. 135).
On this distinctively realist view beauty is intrinsic to that which is said to possess it. As a quality it must be claimed for the thing in its own right. The alternative view is that beauty and every kind of value demands for its existence (real existence but in a non-realist sense) extrinsic relatedness to some person in whom reflective consciousness is emergent and is therefore in our sense a property. No doubt under realist interpretation the beauty is in some sense referred to the thing (Alps or rainbow or diamond) for “the primary function of consciousness is to refer beyond itself” (p. 154). But this has little in common with projicient reference. Nay rather it emphasises the difference between projicient reference and direct apprehension. For under projicient reference a property is bestowed on the thing which thus acquires a new character. But under direct apprehension the quality of beauty is nowise bestowed on or acquired by the thing. It is “revealed” or “disclosed” to the mind which is aware of it and grasps it in a manner all its own. Hence we find that the realist doctrine of beauty implies a doctrine of mind wholly different from ours.
Not all realists however acknowledge beauty as a quality intrinsic to the thing that is said to possess it. According to Professor Alexander though colour is such an intrinsic quality in my sense of these words beauty is not. “In our ordinary experience of colour” he says (S. T. D. II. p. 244) “the colour is separate from the mind and completely independent of it. In our experience of the colour's beauty there is indissoluble union with the mind.” The contention I think comes to this. Colour resides in the thing seen with which an organism having the quality of consciousness may or may not be comp resent. Whether it be so corn-present or not makes no difference to the non-mental existence of colour as such because that colour is intrinsic to the thing as its own emergent quality. On the other hand beauty resides not in the thing only in its intrinsic independence but in the “whole situation.” This we may bracket thus (coloured thing in extrinsic relation to comp resent person with quality of aesthetic consciousness). In that relation “the object has a character which it would not have except for that relation” (p. 240). The doctrine of internal relations (cf. § XIII.) is it seems accepted where beauty is concerned and rejected in respect of colour. Beauty and colour are not alike in kind and demand different kinds of treatment. In other words: If the beautiful object be one term and the person the other term the former gets an acquired character or property (qua beautiful but not qua coloured) in and through its extrinsic relation to the latter.
Thus the beauty of an object is interpreted as “a character superadded to it from its relation to the mind in virtue of which it satisfies or pleases after a certain fashion or aesthetically” (p. 245). And within the relational situation “the beauty is attributed to the object” (p. 246). Mr. Alexander says that “it is the paradox of beauty that its expressiveness belongs to the beautiful thing itself and yet would not be there except for the mind” (p. 292). But is not this just the paradox of all acquired characters as properties that have being through extrinsic relatedness? Quite irrespective of beauty or other value the coin which hangs from my watch-chain has weight which belongs to it as expressive of its gravitational relatedness to the earth; it has for my projicient vision here and now the property of elliptical shape as expressive of its extrinsic relatedness to a pattern of stimulation in my retina; it has too as I believe the property of colour distinctive of a late eighteenth century guinea-piece.
§ XXXIX. The Property of Colour.
In regarding colour as a property of the guinea-piece bestowed thereon under projicient reference and not one of its intrinsic qualities revealed or disclosed to the mind's native power of apprehension I must to my regret part company not only from Mr. Laird but from Mr. Alexander and from many others with whom I would fain travel in quest of reality. But I cannot go with them; and I must give reasons for treading an older path which they have left.
Let me first clear the ground a little. Beyond question we act “as if” colour belongs to this thing or that of its very own right. To act otherwise would generally result in hopeless confusion. The “as if” works admirably. It has pragmatic sanction to the full. This I think no one seriously denies. But I for one cannot pass from “as if in the thing” to “is in the thing in its own right” with an easy conscience.
There is a pretty long chain of events between what actually goes on in the acknowledged thing out there and what actually goes on in a fairly definite area of the occipital cortex. Somewhere either in the whole chain or in one or more than one of its links correlated colour-vision in its aspect of minding and of that which is minded emerges. And within the chain certain intervenient physical and physiological changes are involved. Now I urge to begin with that no matter where its physical basis “really is”—in “the whole situation” or in any specific part of it at one end or the other or somewhere between them—colour must for practical purposes of behaviour be referred to the thing and located therein if it be endorsed by the pragmatic sanction of working so well in its guidance of behaviour. Refer it anywhere else and action inevitably goes astray. I conclude therefore that this pragmatic sanction does not take us one step towards a confident assertion that the colour is intrinsic to the thing itself.
Taking “location” of colour in the thing and nowhere else for granted as matter of common agreement the question is whether on other and more cogent grounds we should “assign” (cf. 167; VIII.) colour as such to an intrinsic place in the thing as one of its own qualities. Let us revert to my lady's diamonds with their lustre and their brilliantly changing play of refraction-colour. She and others delight in their beauty which in part involves these kaleidoscopic colour-changes as the gems are moved under suitable illumination. But for adequate interpretation we must trace the stages or levels of involution from top to bottom. At top is my lady's appreciation of an object of beauty involving her perception of the colour-changes which are characters attributed to that object. Colour-perception involves certain physiological changes in the brain at the level of life; this again involves (if any reliance can be placed in the outcome of research in the field of colour-vision) certain specialised physico-chemical changes in the retina or the choroid or (more comprehensively) in the retino-cerebral system; and this under acknowledgment is due to transmission of electro-magnetic influence from the diamond. Thus at top we fringe off into correlated consciousness aesthetically “qualified” and at bottom we fringe off into physics. There is an enchained set of events subject to emergence from bottom to top. Strike out any of the relevant events at bottom or at top and the beauty of colour is struck out; strike out any of the relevant events between electro-magnetic influence and the events with which percipient consciousness is correlated and colour as such vanishes and surceases.
If the idealist assert that colour lives only at top in the mind irrespective of physical correlates in the organism; or if the realist assert that it lives only at bottom in the thing irrespective of psychical correlates in the organism; I respectfully submit that each goes beyond the evidence. According to the evidence (if I do not misread it) colour lives in the whole situation; in other words it has being in virtue of the extrinsic relatedness of person (body-mind) and thing; but that which has being in virtue of extrinsic relatedness I call a property not a quality intrinsic to the thing. And if either person or thing which thus function as extrinsic terms be absent there is no colour (as Mr. Alexander admits there is no beauty) in being.
Such in brief is my main thesis. Turn aside from it for a moment. In scientific research on the salient features of colour-vision it is justifiable policy to deal with those links of the chain which are chiefly ad rem for the purposes of such research. The departmental question is thus narrowed down to this: What are the specific physico-chemical processes that are involved? Colour as experienced is here taken only as an indication of the presence of these processes under advenient electro-magnetic influence. Just where they occur is a question that arises in the course of that research. But no physiologist or bio-chemist would seek for them outside the organism. If however these highly-specialised processes be in the organism and if colour as experienced be an indication of their presence it seems to follow that for emergent evolution the person (body and mind) is an essential factor in colour-vision. Rub the person off the slate and the physico-chemical processes are not in being and the colour-experience that indicates their presence under correlation cannot exist.
This little digression serves I think to lead to a conclusion in support of my main thesis. What may be said in support of the antithesis?
First it may be asserted that it is not electromagnetic influence as such but colour as such—i.e. an emergent quality of that influence-that determines the physico-chemical events. If so we must ask for the grounds of this assertion. Is it the expression of a fact which must be accepted with natural piety? I think not. I believe that I am wholeheartedly with Mr. Alexander in this matter of natural piety. At any rate we both agree that whenever and wherever emergence occurs it is to be accepted in “the reverent temper which is the mood of natural piety.” In this mood we both accept colour as an emergent quality. But then unfortunately we part company. He says that it is an emergent quality intrinsic to the ruby qua radiant thing; I urge that like beauty it emerges within the bracketed relatedness of ruby and person and is a property referred to the ruby as objectively minded under projicience. Now this I urge is not a matter for acceptance one way or the other under natural piety. It is a matter of interpretation of the facts that are common to both views. One such fact is this-that in order to see the ruby as coloured there must be an eye wherewith to see it. But Mr. Alexander says that the eye is the instrument for apprehending the colour which nowise depends on such instrumentality. “When a physical body is such that the light which it sends out to our eyes has a determinate wave-length that body is red” (Hibbert Journal XX. p. 614). It is that body in itself that has the quality of redness. It is colour as such-an emergent quality of the ruby as a physical thing-that determines the physico-chemical events. Here again I ask: What are the grounds of this assertion? And then so far as I can ascertain it is said that our experience of this colour is a matter of direct visual apprehension. What it is as experienced that it is in itself. Since we assuredly apprehend it as there there it must be; and if there it will exercise influence after its kind on the eye evolved for its reception. Colour-intrinsic to a thing is directly apprehended by a mind should that mind be comp resent with it. If no mind be comp resent it is not apprehended; but it is none the less there. And if we ask for further information with regard to this apprehension we are told in effect it is that through which the realistic world as it is in itself is revealed or disclosed.
We thus open up a further question which crucial as it is cannot here be discussed. One can only indicate its import. For Mr. Alexander mind is minding All that is minded-at any rate under perception-is non-mental. “Compresence” obtains between a person so minding and that which is qua minded non-mental. The crucial question (to be reserved for future consideration) is this: Is there differentiation in such minding-say in perceiving red or green or violet so as to keep within the field of vision? Mr. Alexander says (he will perhaps correct me if I misapprehend his teaching): There is no differentiation in such minding. All the differentiation is in the non-mental colours as minded. The mind just apprehends for 'tis its nature to do so. All I can here say is that I wholeheartedly disagree. I shall hereafter contend that there is just as much differentiation in the minding as substance of the mind as there is in that which is (in my sense) objectively minded as stuff of the mind. Differentiation in the—ed and the—ing is strictly complementary. If there be so much in the one attribute there is that much (no less and no more) in the other attribute. To regard percipient mind as blankly apprehending is-to paraphrase Mr. Alexander's saying with regard to time-not to take seriously the evolution of mind as substance. It robs mental evolution on the plane of perception of its distinguishing features. Under a doctrine of direct apprehension the mind is regarded as an interested spectator in the evolution of our richly-coloured world. Under projicient reference mind even at the perceptual level is a participator in that evolution. Nay more; it is in a sense creator of our objective world with its colour its aroma its music and its beauty. A skeleton world of physical events there is-independent of us under acknowledgment. From its purely physical events there is advenient influence. But it is through projicient reference that it becomes for us a rainbow world with the scent of the shower that has passed by or the patter of retreating raindrops. Such is the corollary from the conclusion that secondary characters are properties extrinsically real in relation to our persons-not our minds only but also our bodily organisation as recipient of advenient influence and as the seat of intervenient processes and thus contributory to projicient reference.
§ XL. “The Bifurcation of Nature.”
What has been said above will no doubt be regarded as open to Professor Whitehead's criticism of such views namely that they imply what he speaks of as a “bifurcation of nature” and introduce the notion of “psychic additions.”
Mr. Whitehead is concerned to keep nature as he defines it wholly uncontaminated by mind. Nature is the intricate and orderly game that is played by non-mental events; mind is an interested spectator recorder and interpreter. Clearly the “nature” thus characterised does not include mind. It is that from which a mind receives information primarily through sense-awareness visual and other. When therefore we are thinking “homogeneously” about nature we are not dealing with the relation of nature to thought; and “this means that nature can be thought of as a closed system whose mutual relations do not require the expression of the fact that they are thought about” (C. N. p. 3). “The understanding which is sought by science is an understanding of relations within nature not of the relation of nature to mind” (pp. 41–47). Clearly on this view mind is no part of “nature” as defined.
Well and good. Here is the mind that somehow has awareness of nature and seeks to interpret it; and there is the nature of which the mind is in some way aware and which is to be interpreted. That seems all right so far if the definitions expressed or implied be accepted. But the trouble Mr. Whitehead finds is that what he calls “the modern account of nature” “is not as it should be merely an account of what the mind knows of nature; but it is also confused with an account of what nature does to the mind” (p. 27). Now what nature does to the mind it is supposed he says to do through causal influence; this is supposed to entail mental appearance say colour; and then this appearance is thrust upon nature through “effluence.” Such an effluent character thrown by the mind on to nature is thus a “psychic addition.” Under this bifurcation of nature an attempt is made to exhibit apparent nature as an effluent of the mind when it is influenced by causal nature. It is thus supposed that “no coherent account can be given of nature as it is disclosed to us in sense-awareness without dragging in its relations to mind” (p. 27).
Now Mr. Whitehead says that “the philosophy of the sciences-conceived as one subject-is the endeavour to exhibit all sciences as one science” (p. 2). “We leave” he says “to metaphysics the synthesis of the knower and the known” (p. 28). But he uses again and again such an expression as “disclosed to sense-awareness” and this since it expresses however naively the relation of known to knower is clearly on his own showing a bit of metaphysics in his sense of the word. Subject to correction I take Mr. Whitehead's position to be this: In so far as there is direct apprehension of “nature” there is when it occurs this relation of “nature” to mind. But being so apprehended makes no difference to “nature” which is (as defined) just what it is and as it is whether it be so apprehended or not. Hence we are justified in restricting attention to that and that only which is or may be apprehended. Now colour is something that is or may be so apprehended; colour therefore is part of “nature.” To say that it is not so is to say that colour is a psychic addition effluent into “nature” from mind-or in other words to accept the vicious notion of a “bifurcation of nature.”
What “modern account of nature” Mr. Whitehead has specially in view I cannot tell. What he says calls up reminiscences of the long-ago days of my youth. Then people did talk of what nature does to the mind and did speak as if there were some sort of flowing forth of colour from the mind into nature. In what exact sense they used such expressions I need not stay to consider. My concern is with the bearing of Mr. Whitehead's criticism on the interpretation I seek here to render clear.
Much of course turns on our widely divergent views with regard to the status of mind. For Mr. Whitehead as I gather mind is an order of being wholly disparate from “nature” and affords the subject matter of metaphysics as distinguished from the physics of “nature.” For me in the good company of Spinoza and his followers mind is within one of the two “attributes” of nature. It is the natural correlate of certain physical events which belong to the other attribute. There is for us no effluence from either attribute to the other; nor is there any causal influence of the one on the other. There can therefore be for us no psychic additions to physical nature. What there are if I may so put it are psychical signs attaching to certain physical events-the sign in one attribute the physical events in the other. Colour is such a psychical sign in the correlated attribute which accompanies certain processes in the physical attribute when both attributes reach a late stage of evolutionary development.
Where then are the physical events with which colour-signs are correlated? I am content to reply that they are the correlates of a chain of organic events extending from the retinal receptor-pattern to the “visual centre” of the occipital cortex. As I read the evidence (of course it may be otherwise read) when the central factors in such and such a chain of physical events are in being-no matter how they are physically called into being-such and such colour-signs correlated therewith are also in being.
But of what is such colour the psychical sign? We must here distinguish that of which it may be the sign for the interpreter from that of which it is the sign for the conscious percipient. From the point of view of the interpreter it may be the sign (a) of the physiological events in the visual centre with which it is correlated; or (b) of other events within the organism that are involved—e.g. the chemical changes in the retina or the choroid. But from the point of view of the conscious percipient it is as a matter of primary genesis and to the end of behaviour a sign of the presence of some thing in the external world which has become an object of vision. The sign is within the person and is correlated with very complex and highly differentiated chemical processes within the organism. But what is signified for the percipient is not within the person; nor is it within the organism. What is projiciently signified is a source of advenient physical influence.
Now the value of a sign is that it shall have reference to something signified. But surely this does not imply or even suggest that the sign is in any valid sense effluent on to that which is thereby signified. The red which is the psychical sign of certain physical events in the ruby is no more effluent to the ruby than is the word “red” or the name “ruby” effluent thereto. Herein lies the point of much that Berkeley said concerning visual language. It is a sign of something quite different from that which as sign it is. Hence it can be a psychical sign of physical events. This we express by saying that the sign has reference to that which is signified. And the good of such reference is that the sign shall serve as a guide to behaviour towards the thing that is signified. Hence the evolutionary stress on behaviour on the plane of life-genetically purely “behaviouristic”—as the natural precursor of reference on the plane of mind. I speak of the sign as “projicient” to emphasise (1) its correlation with that which occurs within the person and (2) its reference to something signified at a distance from that person.
In its primary genesis then this projicient reference is to a source of advenient physical influence. But when the visual centre of the occipital cortex is secondarily excited along some neurone-route from other parts of the brain there is the psychic sign in the absence of the external source of effluence normally signified. None the less there is projicient reference of the sign to some located position in the external world and there is a visual image. Its location is probably due to the substantial similarity of the complex set of intervenient events concerned in such location—e.g. focussing of the eyes but also much else.
Let us descend to a little detail. On waking this morning my eyes fell on the window through which streamed brilliant sunshine. I closed them swiftly. After a brief interval there appeared at the same distance a full rich violet-purple after-effect window shaped round-headed and crossed by a dark horizontal band nearly neutral grey with a soupcon of green answering to the lower frame above the open part of the window. It moved jerkily with the movements of my closed eyes but preserved the same apparent distance under location. After another brief interval it became (still at the same distance and of the same shape) a fainter rather dirty green or greenish yellow; and so on. I speak of these colour-effects as projicient just as all visual images as such are projicient.
It may now be comprehensible why I should not speak of the colours which appear in the positive or negative after-sensations as psychical additions to physical nature. None the less they may be spoken of as psychical correlates of something that does occur in nature (as defined by Mr. Whitehead) i.e. of something going on somewhere. Then where? In my retino-cerebral system. And how evoked? Primarily by electro-magnetic influence from some effluent source. Also as physico-chemical changes consequent thereon i.e. as aftereffects not due to further influence from without. Secondarily by revival of neural process in the visual centre. There may also in this case be renewal of chemical processes in the retina or choroid through an outstroke from the brain; but whether this is so or not it is difficult to determine. In any case the colour is referred to something however intangible outside us. I speak of this colour as projicient but if I speak of it as effluent into physical nature I speak inadvisably even if (as I suspect) I am not talking nonsense from the standpoint of my own interpretation. I am well aware that there are other interpretations-that for example according to which all images are not only objective but also non-mental; but I am here concerned to make mine as clear as I can.
Now suppose instead of after-effects or of images one considers the red of the ruby or the hues of the rainbow or the colours of thin mineral slices under a polarising microscope-it matters not which-colour-signs are in each case the psychical correlates of the cortical occurrence and all that this involves in certain highly specialised physico-chemical events within me. If there be no such events there are no such correlates. But these correlates are also the psychic signs attaching to electromagnetic events in things outside me which are thereby signified. It is for the physicist to determine the exact nature of these events. They may continue indefinitely whether they be perceived or not; but only in certain organisms do they evoke those specialised physical and physiological events which have as psychical correlates modes of colour-experience.
On the above showing I regard it as equally inadmissible to say that colour as such is effluent from “nature” or that it is effluent into “nature” as defined by Mr. Whitehead. It is a projicient sign begotten of the psychical correlates of processes that occur in the organism.
Lest it be said that I shirk details as to the kind of chemical process that is inferentially involved in colour-vision I may add that my own provisional interpretation (stated with the utmost brevity) is something like this:
(1) The specific event is a “reversible” chemical process or the net result of two such processes say α+ α− and β+ α−
(2) These processes are due to light-waves (electro-magnetic pulses) ranging say from d to j; where d may be something like 400 billion vibrations—per sec. and j. something approaching 800 billion—per sec.
(3) Express the suggested relation of light influence to chemical changes in the diagrammatic form of a truncated pyramid (Fig. 4).
(4) Now tabulate these results and introduce the correlated psychic colour-signs.
Light Influences.
Chemical Process.
Psychic Colour-sign.
This gives the range of the colours of the spectrum.
(5) Any combination of wave-lengths (say f and h) which gives α−β− (in due proportion) gives also its correlated colour-sign (say green).
(6) Now the table given above leaves out of account purple which does not occur in the spectrum. But it also leaves out of account the combinationα.
(7) We must therefore add to our table one more item thus:
d and j
(8) If we have say 75% α+ with 25% β+ we get a reddish purple; or say 25% α+ with 75% β+ we have violet-purple. Similarly with say α+β− in differing proportions; and so on.
(9) In other words and more generally any colour will shade into its neighbouring colour in accordance with the proportional amount of α-process and of β-process in their positive and negative phases.
(10) The correlation of α− with blue-green and of β− with yellow-green may not be accepted. And the truncated pyramid of my diagram may be rejected. It serves (as I think) to afford an avenue towards the reconciliation of the so-called “four-colour” and “three-colour theories and will presumably find acceptance with neither party to a long controversy.
But the cardinal questions are these: Are chemical processes involved in colour-vision? If so can the psychical colour-signs correlated therewith properly be described as effluent either from or into nature under Mr. Whitehead's definition of nature?

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