In view of this fact of mutual participation of nature and idea among the sciences that use each other, I have myself conceived, and in another place have given expression to, what appropriately may be called a physical psychology or epistemology.'[1] This new hybrid science is especially concerned with nothing more nor less than those substitutes, disguises, or indirections, really present in all the physical sciences, for the peculiar nature, for the peculiar sort of unity, intensive instead of extensive or qualitative instead of quantitative, or say also even vital and spiritual instead of physical, which is always associated with mind. In conservation of matter, energy, what you will, in plenitude, in motion as only relative and so as always under a principle of uniformity and constancy or even immobility, in motion too as inclining to vibration, which suggests poise or tension, or to rotation, in which we see rest as well as motion, and finally, not to extend what might be a long list, in the infinity of space and time or of quantity, the physical sciences have hidden entrances for the silent, usually unnoticed admission of what is psychical. But I may seem to be jumping too far, to be presuming too much. Then put the case in this way—not quite so direct, but to the same goal. All of these conceptions, so necessary to a "working" physical science, need very little examination to be seen to be treacherous to the physical standpoint and its peculiar categories. One might as well try to make water unsupported assume definiteness of form as to conceive the conservation of energy or plenitude or the relativity of motion in the character of what is physical, or at least of what is properly and conventionally physical. Being treacherous, then, to the physical science that has conceived them, they are, as was said, doors for what is not physical; hidden doors, perhaps, but certainly doors to be opened at will; and by them mind is bound to enter the physical world and its sciences. To those familiar with the history of philosophy, the speculation of the early Greek thinkers, notably Anaximander, Parmenides, and Anaxagoras, will afford illustration of the physical view running, in spite of itself, into treacherous conceptions, and eventually reaching the discovery of their treachery and with it the idea of mind or Nous.[2]

So for science is the material world, what properly it is often said to be, a sort of dark mirror of man's inner life, of his psychical nature. Physical science as consciousness of the outer material world is not, and has itself shown that it cannot be, merely and exclusively physical. By virtue of its working hypotheses, which are as secret doorways, it is psychical also. Though darkly and indirectly it is our human self-consciousness. Perhaps it is our self-consciousness rendered impersonal or the self seen through the mirror of not-self or through the disguise of what a photographer would call a "negative"; and, if it may be so described, we are reminded of Burns:—

O wad some power the giftie gie us,
To see oursels as others see us!
It wad frae monie a blunder free us,
And foolish notion.

Only the bonnie Robert himself was too much of a specialist in poetry to see that natural science was the very thing he prayed for.

And just as there is thus a physical psychology, so in like manner there is a psychological or epistemological physics, which in its turn is concerned with the indirections, or doors in the panelling, present in all the psychical sciences, for those very physical things quantity and matter. The devil will have his due; even an optimistic theology has to recognize him. And psychology has a sensuous self, the self of the purely sensuous consciousness, which has always involved it in a curious psychical atomism, a projection, in a word, of the physical on the plane of the psychical. Sensationalism, too, as a psychological theory in the history of thought has always been associated with materialism.

With regard, then, to the separation even of the psychical and the physical sciences, which obviously has at its base the distinction between mind and matter, we observe that our principle of affinity and mutual participation still holds. By a sort of projection or reproduction mind and matter both appear, the one openly, the other in disguise, in each kind of science. However unawares, the physical entertains mind; the psychical matter; and specialism, so far as standing for anything more than scientific method, has to withdraw from its last stronghold. The very dreaming of the scientific imagination is its undoing.

For other evidence against the integrity and adequacy of specialism, showing how mind defies specialism and conserves its indivisible universe, there are the following simple but certainly interesting facts. All the different sciences, however special and however apparently alien in subject matter, are wont to use the same general methods—as, for example, the laboratory or experimental method or the historical method, the fatal consequences of which to the cause of pure specialism may easily be inferred. History is famous for overcoming differences. The common interest in mathematics must also be mentioned, for mathematics, through its latest developments in danger of turning into a pure logic, is quite independent of all those material differences that separate the different sciences. It is formal and universal, not special; so that the special science that would also be mathematical appears somehow to be at least in aim as universal as it is special. Perhaps mathematics more than anything else has fed the voracity which we have seen veracity to exact. Has it not been the chief agent in the virtual annihilation of the barriers between physics and chemistry? This particular mingling of the special sciences has been mentioned here already, but mathematics is threatening the party-walls of all the other sciences also. Further, what are we to infer from the idea that all sciences seek law? Certainly law is not special as science has seemed to be. Somehow law is not many, but one. Many laws can only be different phases or cases of one law. The very essence of law is to be one and single and all-embracing. To put the case theologically, could any one suppose that God made the laws of chemistry and sociology and psychology as so many separate and independent enactments? On such a supposition he had been a strange God indeed, lacking the very thing, unity of being and character, which men have come to associate with divinity, and what theology demands of God, science, even against its own specialism, must demand of its object. Again, the way in which by implication, when not openly, one science is given to handing over its hardest problems to another is very instructive as well as amusing. Not many years ago I was present at a joint meeting, a good-natured and doubtless honestly ambitious conference of biologists, physiologists, and psychologists, and the addresses then made have often reminded me of one of Thomas Nast's famous cartoons: A closed ring of political grafters, none other than the notorious Tweed and his followers, each pointing to his neighbour and putting on him the responsibility of a very embarrassing situation. "Find the rogue" was the artist's inscription; but with apologies for the association, we can easily change it to "Find the special science." And, lastly, in this list of the simple evidences against an adequate specialism there are the conspicuous analogies other than those of common method or common interest in law, which are always easily traced among the sciences, even the sciences in the opposite camps of matter and mind, of any particular time. Atomism in physics is contemporary with atomism in psychology and with individualism in political philosophy; a monarchical politics with an anthropomorphic, creationalistic theology and an also monarchical physically centred astronomy, whether heliocentric or geocentric; and a Newtonian astronomy, which really makes a law or force instead of an individual body the centre and control of the solar system, with democracy or constitutionalism, and with inductive instead of deductive logic and naturalistic instead of dogmatic theology; so that at no time, whatever the scientist's special interest, whatever his special syllable, can he fail to have at least a formal sympathy with others. Such analogies among the sciences, so often recognized and so absorbingly interesting to the students of the history of thought, if not exactly doors in the panelling, may be said to make the panelled partitions at least translucent if not unsubstantial and transparent.

But the most important fact in illustration of our case against specialism is yet to be considered, and unfortunately it takes us where to some the waters may seem dangerously deep. Not only for reasons already given and emphasized is the special science a misnomer, a contradiction in terms, except in so far as specialism be taken merely as an incident, not without its humour, of scientific method, but also for the same reasons (and chiefly because the truth and reality of the universe are bound to be conserved) every special science must sooner or later develop its doctrines either into direct paradoxes or into tenets that oppose and contradict each other. Thus, as has been shown, specialism in science is itself a paradox, and, as now asserted, every special science assuming precise form and real validity becomes a home of paradoxical or contradictory doctrines. Indeed, these doctrines just through their opposition appear be the most effective agents of that compensation for neglected points of view, or conservation of all points of view, which we are insisting is for ever forced upon the scientific specialist. In the cases of physical epistemology and epistemological physics we have already seen doctrines working to this end. In those cases the real treachery to the avowed standpoints lay in virtual when not open contradiction. And, for the general principles, is it not quite clear that nothing so surely as contradiction in any given point of view, or in the specific doctrines developed under it, can serve the interests of any other points of view? I have heard it said, but by whom originally I do not know, that a paradox or contradiction was only the mind on tiptoe struggling to look over a very high wall.

The point is just this. The special science, because special or partial and because at the same time courting scientific character or validity, that is, conformity with reality, must be relative, formal, abstract, artificial, unreal, but also for exactly the same reason it must contrive to admit to its conceptions other view-points than its own. Its own peculiar view-point is relative, but that it may attain actual validity it is bound to overcome its relativity by admitting, secretly perhaps yet not less truly, other points of view; and paradox or contradiction is the natural door for such admissions, the original view-point being tenacious to the last. Physics says: "I will be physics through thick and thin; I will be physics though the heavens fall and though dreadful paradoxes arise"; and in like manner psychology cries aloud: "I will be psychology though I suffer from a splitting dualism for my pains." Have you, gentle reader, never held and held and held to some particular notion about things, modifying the details perhaps little by little, but always imagining yourself strictly loyal to the old, old view, and then suddenly discovered your consciousness alive with contradictions? If you have, you know, possibly too well, the natural history of every special science, and also you can sympathize deeply with the hen and her cherished chicks that proved ugly ducklings. The special science, I repeat, must be hospitable, however grudgingly, to strangers, though at the expense of becoming thoroughly divided against itself. Such hospitality is an obligation—call it logical if you will, or moral or metaphysical, for the name matters not if it only suggests coercion—which is not less binding upon the scientific spirit than upon the spirit of racial unity, always urgently present in you and me. You and I may be so special or exclusive as to drive strangers from our doors, but an impulse to call them back and give them entertainment always follows—an impulse that is only the necessary reaction of the expulsion. Humanity is indivisible in spite of our asserted exclusiveness, and nature is indivisible, too, in spite of specialism. Partiality of any sort, along any line, in any field, can never long persist without, though often darkly and indirectly, though by the way of bold, unrecognized, or unconfessed paradox, receiving from outside all that it would exclude. I am not merely repeating. At first, we saw only that the scientific imagination brought to the special science as its working hypotheses certain conserving or compensating conceptions; then, that these conceptions involved treachery to the science that harboured them; but now we are face to face with the fact that their complete, their most effective form is the paradox.

Would that I had the ability to write with the penetration and the clearness of statement that the subject should certainly elicit, upon the strange equanimity with which mankind, in science or in practical life, receives and faces a direct negative or an open contradiction. Perhaps the habit of easy division into positive and negative, the ready resort to dichotomy, explains the mystery; perhaps the fact that negation or opposition is and can only be in kind, that there never is or can be any real change or need of change in a mere negation, is at least an important factor in the case; perhaps, again, the very hopelessness of the dualism, which a flat, unequivocal negation plainly involves, is also to the point; but, beyond all peradventure, we do accept the direct negative with a patience, even an indifference, that may greatly assist our natural conservatism, whether of thought or life, but that on being recognized certainly does arouse our wonder. Good and its opposite evil, true and false, real and unreal, unity and plurality, life and death, the indivisible and the divisible, rest and motion, plenum and vacuum, immaterial and material, actuality and illusion, lawfulness and lawlessness: these and so many other opposites are the common stock-in-trade of our living and thinking, and we accept and use them with a complacency that cannot easily be exaggerated. Yet the negative in each and every one of them holds the future of the universe in the palm of its hand. And the special scientist before his inevitable paradoxes is as conservative and as complacent as the rest of us.