perhaps as great a mistake to assume that it can be anything determinate in itself apart from all relations to other things. By the physicist this mistake can hardly be made: for him action and reaction are strictly correlative: a material system can do no work on itself. For the biologist, again, organism and environment are invariably complementary. But in psychology, when presentations are regarded as subjective modifications, we have this mistaken isolation in a glaring form, and all the hopeless difficulties of what is called “ subjective idealism ” are the result. Subjective modifications no doubt are always one constituent of individual experience, but always as correlative to objective modifications or change in the objective continuum. If experience were throughout subjective, not merely would the term subjective itself be meaningless, not merely would the conception of the objective never arise, but the entirely impersonal and intransitive process that remained, though it might be described as absolute becoming, could not be called even solipsism, least of all real experience. Common Sense, then, is right in positing, wherever experience is inferred, (1) a factor answering to what we know as self, and (2) another factor answering to what each of us knows as the world. It is further right in regarding the world which each one immediately knows as a coloured, sounding, tangible world, more exactly as a world of sensible qualities. The assumption of naive realism, that the world as each one knows it exists as such independently of him, is questionable. But this assumption goes beyond individual experience, and does not, indeed could not, arise at this standpoint.
Answering to the individuality and unity of the subjective factor, there is a corresponding unity and individuality of the objective. Every Ego has it-s correlative Non-Ego, whence in the end such familiar saying as quot lzornines tot sentential and the like. The doctrine of Leibnitz, that “ each monad is a living mirror. representative of the universe according to its point of view, ” will, with obvious reservations, occur to many as illustrative here. In particular, Leibnitz emphasized one point on which psychology will do well to insist. “Since the world is a plenum, ” he begins, “ all things are connected together and everybody acts upon every other, more or less, according to their distance, and is affected by their reaction; hence each monad is a living mirror, " &c. Subject and Object, or (as it will be clearer in this connexion to say) Ego and Non-Ego, are then not merely logically a universe, but actually the universe, so that, as Leibnitz put it, “ He who sees all could read in each what is happening everywhere ” (M on ado logy, § 61). Though every individual experience is unique, yet the more Egol is similar to Egog the more their complementaries Non-Egol, Non-Egog are likewise similar; much as two perspective projections are more similar the more adjacent their points of sight, and more similar as regards a given position the greater its distance from both points. No doubt we must also make a very extensive use of the hypothesis of subconsciousness, just as Leibnitz did, before we can say that the universe is the objective factor in each and every individual's experience. But we shall have in any case to allow that, besides the strictly limited “ content ” rising above the threshold of consciousness, there is an indefinite extension of the presentational continuum beyond it. And the Leibnitzian Monadology helps us also to clear up a certain confusion that besets terms such as “content of consciousness, ” or “ finite centre of experience ” -a barbarous but intelligible phrase that has recently appeared-the confusion, that is, with a mosaic of mutually exclusive areas, or with a scheme of mutually exclusive logical compartments. Consciousnesses, though in one respect mutually exclusive, do not limit each other in this fashion. For there is a sense in which all individual experiences are absolutely the same, though relatively different as to their point of view, i.e. as to the manner in which for each the same absolute whole is sundered into subjective and objective factors.
This way of looking at the facts of mind helps, again, to dispel the obscurity investing such terms as subjective, inter subjective, 1 Principles of Nature and Grace, § 3.
trans subjective and objective, as these occur in psychological or epistemological discussions. For the psychologist must maintain that no experience is merely subjective: it is only epistemologists (notably Kant) who so describe individual experience, because objects experienced in their concrete particularity pertain, like so many idiosyncrasies, to the individual alone. In contrast with this, epistemologists then describe universal experience-the objects in which are the same for every experiment —as objective experience par excellence. And so has arisen the time-honoured opposition of Sense-knowledge and Thoughtknowledge: so too has arisen the dualism of Empiricism and Rationalism, which Kant sought to surmount by logical analysis. It is in the endeavour to supplement this analysis by a psychological genesis that the terms inter subjective and trans subjective prove useful. The problem for psychology is to ascertain the successive stages in the advance from the one form of experience or knowledge to the other. “ When ten men look at the sun or the moon, ” said Reid, “ they all see the same individual object.” But according to Hamilton this statement is not “ philosophically correct . the truth is that each of these persons sees a different object .... It is not by perception but by a process of reasoning that we connect the objects of sense with existences beyond the sphere of immediate knowledge.”2 Now it is to this “ beyond ” that the term trans subjective is applied, and the question before us is: How do individual subjects thus get beyond the immanence or immediacy with which all experience begins? By a “ process of reasoning, ” it is said. But it is at least true in fact, whether necessarily true or not, that such reasoning is the result of social intercourse. Further, it will be generally allowed that Kant's Analytik, before referred to, has made plain the insufficiency of merely formal reasoning to yield the categories of Substance, Cause and End, by which We pass from mere perceptual experience to that wider experience which transcends it. And psychology, again, may claim to have shown that in fact these categories are the result of that reflective self-consciousness to which social intercourse first gives rise.
But such intercourse, it has been urged, presupposes the common ground between subject and subject which it is meant to explain. How, it is asked, if every subject is confined to his own unique experience, does this inter subjective intercourse ever arise? If no progress towards intellective synthesis were possible before lntersubjective intercourse began, such intercourse, as presupposing something more than immediate sense-knowledge, obviously never could begin! Let us illustrate by an analogy which Leibn1tz's association of experience with a “ point of view " at once suggests. If it were possible for the terrestrial astronomer to obtain observations of the heavens from astronomers in the neighbouring stars, he would be able to map in three dimensions constellations which now he can only represent in two. But unless he had ascertained unaided the heliocentric parallax of these neighbouring stars, he would have no means of distinguishing them as near from the distant myriads besides, or of understanding the data he might receive; and unless he had first of all determined the still humbler geocentric parallax of our sun, those heliocentric parallaxes would have been unattainable. So in like manner we may say “ inter subjective parallax " presupposes what we may call “subjective parallax, ” and even this the psychological duality of object and subject. But such subjective parallax or acquaintance with other like selves is the direct outcome of the extended range in time which memory proper secures; and when in this way self has become an object, resembling objects become other selves or “ ejects, " to adopt with slight modification a term originated by the late W. K. Clifiord. We may be quite sure that his faithful dog is as little of a solipsist as the noble savage whom he accompanies. Indeed, the rudiments of the social factor are, if we may judge by biological evidence, to be found very early. Sexual union in the physiological sense occurs in all but the lowest Metazoa, pairing and courtship are frequent among insects, while “ among the cold-blooded fishes the battle of the stickleback with his rivals, his captivating manoeuvres to lead the female to the nest which he has built, his mad dance of passion around her, and his subsequent jealous guarding of the nest, have often been observed and admired.” 4 Among birds and mammals 2 Lectures on Metaphysics, ii. 153.
3 And it is precisely for want of this mediation that Kant's “ two stems of human knowledge, which perhaps may spring from a common but to us unknown root, " leave epistemology still more or less hampered with the old dualism of sense and understanding. 4 Evolution of Sex, by Geddes and Thomson, 1st ed. p. 265.