The Arithmetical Paradox: The Oneness of Mind

I find it utterly impossible to form an idea about either how, for example, my own conscious mind (that I feel to be one) should have originated by integration of the conscious- nesses of the cells (or some of them) that form my body, or how it should at every moment of my life be, as it were, their resultant. One would think that such a ‘com- monwealth of cells’ as each of us is would be the occasion par excellence for mind to exhibit plurality if it were at all able to do so. The expression ‘commonwealth’ or ‘state of cells’ (2ellstaat) is nowadays no longer to be regarded as a metaphor. Listen to Sherrington:

To declare that, of the component cells that go to make us up, each one is an individual self-centred life is no mere phrase. I t is not a mere convenience for descriptive purposes. The cell as a component of the body is not only a visibly demarcated unit but a unit-life centred on itself. I t leads its own life … The cell is a unit-life, and our life which in its turn is a unitary life consists utterly of the cell-lives.

But this story can be followed up in more detail and more concretely. Both the pathology of the brain and physiological investigations on sense perception speak unequivocally in favour of a regional separation of the sensorium into domains whose far-reaching independence is amazing because it would let us expect to find these regions associated with independent domains of the mind; but they are not. A particularly characteristic instance is the following. If you look at a distant landscape first in the ordinary way with both eyes open, then with the right eye alone, shutting the left, then the other way round, you find no noticeable difference. The psychic visional space is in all three cases identically the same. Now this might very well be due to the fact that from corresponding nerve- ends on the retina the stimulus is transferred to the same centre in the brain where ’the perception is manufactured’ - just as, for example, in my house the knob at the entrance door and the one in my wife’s bedroom activate the same bell, situated above the kitchen door. This would be the easiest explanation; but it is wrong.

Sherri~gton tells us of very interesting experiments on the thresnold frequency of flickering. I shall try to give you as brief an account as possible. Think of a miniature lighthouse set up in the laboratory and giving off a great many flashes per second, say 40 or 60 or 80 or 100. As you increase the frequency of the flashes the flickering disappears at a definite frequency, depending on the experimental details; and the onlooker, whom we suppose to watch with both eyes in the ordinary way, sees then a continuous light. 2 Let this threshold frequency be 60 per second in given circumstances.

In a second experiment, with nothing else changed, a suitable contraption allows only every second flash to reach the right eye, every other flash to reach the left eye, so that every eye receives only 30 flashes per second. If the stimuli were conducted to the same physiological centre, this should make no difference: if I press the button before my entrance door, say every two seconds, and my wife does the same in her bedroom, but alternately with me, the kitchen bell will ring every second, just the same as if one of us had pressed his button every second or both of us had done so synchronously every second.

However, in the second flicker experiment this is not so. Thirty flashes to the right eye plus alternating 30 flashes to the left are far from sufficient to remove the sensation of flickering; double the frequency is required for that, namely, 60 to the right and 60 to the left, if both eyes are open. Let me give you the main conclusion in Sherrington’s own words:

It is not spatial conjunction of cerebral mechanism which combines the two reports . . . I t is much as though the right-and left-eye images were seen each by one of two observers and the minds of the two observers were combined to a single mind. It is as though the right-eye and left-eye perceptions are elaborated singly and then psychically combined to one … I t is as if each eye had a separate sensorium of considerable dignity proper to itself, in which mental processes based on that eye were developed up to even full percep- tual levels. Such would amount physiologically to a visual sub- brain. There would be two such sub··brains, one for the right eye and one for the left eye. Contemporaneity of action rather than structural union seems to provide their mental collaboration.

This is followed by very general considerations, of which I shall again pick out only the most characteristic passages: Are there thus quasi-independent sub-brains based on the several modalities of sense? In the roof-brain the old ‘five’ senses instead of being merged inextricably in one another and further submerged under mechanism of higher order are still plain to find, each demarcated in its separate sphere. How far is the mind a collection of quasi-independent perceptual minds integrated psychically in large measure by temporal concurrence of experience? … When it is a question of ‘mind’ the nervous system does not integrate itself by centralization upon a pontifical cell. Rather it elaborates a millionfold democracy whose each unit is a cell … the concrete life compounded of sublives reveals, although integrated, its additive nature and declares itself an affair of minute foci of life acting together … When however we turn to the mind there is nothing of all this. The single nerve-cell is never a miniature brain. The cellular constitution of the body need not be for any hint of it from ‘mind’ … A single pontifical brain-cell could not assure to the mental reaction a character more unified, and non-atomic than does the roof-brain’s multitudinous sheet of cells. Matter and energy seem granular in structure, and so does ’life’, but not so mind.

1 have quoted you the passages which have most impressed me. Sherrington, with his superior knowledge of what is actually going on in a living body, is seen struggling with a paradox which in his candidness and absolute intellectual sincerity he does not try to hide away or explain away (as many others would have done, nay have done), but he almost brutally exposes it, knowing very well that this is the only way of driving any problem in science or philosophy nearer towards its solution, while by plastering it over with ’nice’ phrases you prevent progress and make the antinomy perennial (not forever, but until someone notices your fraud).