There remains for consideration the place of the cognitive relation in Spencer's philosophy of science. We need not here discuss his transfigured realism. Apart from the customary references to the Unknowable, of which what is knowable is said to be symbolic, it comes to little more than laying special emphasis on the truism that what is known in the so-called objective world involves the process of knowing; from which it follows that, apart from knowing it the objective world cannot be known. From this Spencer draws the conclusion that terms in cognitive relatedness have their very nature determined in and through that relatedness, and cannot in themselves be what they are, and as they are, in the field of cognitive symbolism. This may or may not be true. I am one of those who question the validity of the arguments in favour of this conclusion. Since, however, the philosophy of science deals only with the knowable—of which the so-called appearances with which we have direct acquaintance are the primary data—we need not here trouble ourselves with the controversy between realists and symbolists. Even on Spencer's view the world as symbolized is the real world for science.
Now one way of expressing the fact that the cognitive relation is always present where knowledge is concerned is to proclaim 'the truth that our states of consciousness are the only things we can know'.[64] But it is a terribly ambiguous way of expressing the fact. What is here meant by a state of consciousness? So far as cognition is concerned it is, or at any rate it involves, a relationship between something known and the organism, as knowing—for Spencer assuredly the organism, though a so-called inner aspect therein. Of course it is a very complex relationship. It comprises relations in what is known, and relations in the organism as knowing. Hence Spencer defines life, psychical as well as physical, as 'the continuous adjustment of internal relations to external relations'.[65]
'That which distinguishes Psychology is that each of its propositions takes account both of the connected internal phenomena and of the connected external phenomena to which they refer. It is not only the one, nor only the other, that characterises cognition. It is the connexion between these two connexions.'[66]
So far well. Cognition is a very complex network of relatedness involving many terms. What are these terms? For Spencer the internal terms are ultimately nervous (= psychic) shocks in highly integrated aggregates; and the external terms are, proximately at least, things in the environment. But both alike are spoken of as states of consciousness. There is surely an opening for ambiguity here. Sometimes, too, the words subjective affections are used in place of states of consciousness. 'Thus we are brought to the conclusion that what we are conscious of as properties of matter, even down to its weight and resistance, are but subjective affections.'[67] Well, these states of consciousness, these subjective affections, fall into two great classes—the vivid and the faint. The former, which we know as sensations, accompany direct and therefore strong excitations of the nerve-centres; the latter, which we know as remembered sensations, or ideas of sensations, accompany indirect and therefore weak excitations of the same nerve-centres.[68] And then we are told that the aggregate of the faint is what we call the mind, the subject, the ego; the aggregate of the vivid is what we call the external world, the object, the non-ego.[69] It would seem, then, that the aggregate of vivid subjective affections is the objective world so far as knowable. To say the least of it, this terminology is somewhat perplexing.
No doubt our knowledge of the external world involves a subtle and intricate inter-relation of what is experienced vividly and what is experienced faintly—of what is actually presented and what is ideally re-presented. The distinction between them is a valid one. But when Spencer equates this distinction with that between the external world and the mind, as he does in the passages to which I have referred, the validity of his procedure is seriously open to question.
It must be confessed that an adequate analysis of cognitive relatedness on scientific lines is not to be found in Spencer's works. I am not sure that it is yet to be found in the works of any other philosopher, though there are many signs that the difficult problems it involves are receiving serious attention. This much seems certain, for those who accept the spirit, though not perhaps the letter, of Spencer's teaching: that there it is as a constitutive mode of relatedness in the realm of nature, and that, if it forms part of the evolutionary scheme, if it is present in the conclusion, so far reached, though it was absent in the physico-chemical premises, if it is to be included in a philosophy of science it must be dealt with by that philosophy on lines strictly analogous to those on which any other relational problem is treated. Firmly as we may believe in the reality of Source, we must not call to our aid some psychic entity, some entelechy, some élan vital, to help us out of our difficulties; for one and all of these lie wholly outside the universe of discourse of science; and not one of them affords the smallest help in solving a single scientific problem in a manner that is itself scientific.
We have seen that Spencer believed that the task of psychology is to investigate the correlation of external and internal relations, and, in that sense, itself to correlate them within a scientific interpretation. Now the outcome of the former correlation is some form of behaviour or conduct on the part of the organism. No doubt such behaviour affords data to be dealt with in subsequent cognition. But it implies the prior cognition which leads up to it; and it is this prior cognition, abstracted from the behaviour to which it leads, that we have to consider. It is so terribly complex that it is difficult to deal with it comprehensibly in a brief space. Let me, however, try to do so, at least in tentative outline. There occurs, let us say, an external event in the physical world, such as the motion of a billiard-ball across the table; and when during its progress this stimulates the retina, there is an internal physico-chemical process which runs its course in retina, optic nerves, and the central nervous system. We may regard these two processes, external and internal, as so far, of like physical order. With adequate knowledge the two could, in some measure, be serially correlated as such. But the physico-chemical processes in the organism are not only of this physical type. They are vital or physiological as well. And this makes a real difference. Of course this statement is open to question. But I, for one, believe that there are specific relations present in physiological processes, qua vital, other than those of the physico-chemical type—relations which are effective and which require a distinctive name. So far I am a vitalist. At some stage of evolution these new modes of effective relatedness came into being, whereas in the fire-mist and for long afterwards they were not in being. None the less when they did actually come into being, under conditions of which we are at present ignorant—though not so ignorant as we were—they were dependent upon, and, for our interpretation, they logically imply, the physico-chemical relations which are also present. In any given case they further imply, through heredity-relatedness, the evolutionary history of the organism in which they obtain. This so-called historical element in biology no doubt involves a characteristic vital relationship. But, I take it, the physico-chemical constitution of any inorganic compound, and of any molecule therein, has also its history—has relationship to past occurrences within its type, which have helped to make it what it is. Still, in the organism the relation to past happenings has a quite distinctive form which we deal with in terms of heredity. See, then, how we stand so far. The internal physiological process implies a long chain of heredity-relationships through which the organism is prepared for its occurrence. It also implies a physico-chemical basis, an underlying[70] physico-chemical process. And this implies as a condition of its occurrence, the external event, the passage of the billiard-ball across the table. In a broad sense we may say that the inner process knows the external event which is a condition of its occurrence. But we have not yet reached cognition of the psychological type.
Before passing on to indicate, in tentative outline, the nature of this higher mode of relatedness, I pause to note two points. The first is that knowing in that extended sense which I have borrowed,[71] is essentially selective in its nature. The physiological process, in the case I have taken, knows only that external event which is directly before the eyes and which is serially correlated with changes in the retinal images through the stimulation of specialized receptors. Of other external events it has no such knowledge. Compare this with the gravitative knowledge—if a yet wider extension of the meaning of the word be permitted—which the earth has of the sun and all the other members of the solar system—nay more, in degrees perhaps infinitesimal, of all other material bodies in the universe. The motion of the earth in its orbit implies the whole of this vast field of gravitative relatedness. The existing orbital motion at any moment implies, too, the preceding motion which it has, in a sense, inherited from the past. Abolish the rest of the universe at this moment and the earth's motion would cease to be orbital. In virtue of its 'inheritance from the past', it would continue at uniform velocity in one direction. The continuous change of direction and velocity we observe, is a response which implies gravitative knowledge. In a sense, then, the whole solar system is known by the earth as it swings in its orbit.
The second point may be introduced by a question. Granted that we may say, in a very liberal sense, that the earth in its motion has this gravitative knowledge—is such knowledge accompanied by awareness? We do not know. But the point I have in mind is this, that the question itself is vague. Awareness of what? There must be awareness of something; and a definite question should be directed towards the nature of that something. For example: is the earth aware of its own motion? Or is it aware of the solar system? Or is it aware of the relation of the one to the other? If it be said that the second of these is meant when we ask whether the knowledge is accompanied by awareness, well and good. The answer will serve to define the question. Take now a case of biological knowledge. Are the plants in the cottager's window, when they grow towards the light, aware of a process in their own tissues? Or are they aware of the sunshine? Or are they in some measure aware of the connexion between the one and the other? To all these questions we must answer, I suppose, that we do not know. But it may have been worth while to ask them in a definite way.