mistakes here and there, a letter or two altered, or left out. Place the words in a dark room in front of a person who, of course, does not know what has been written. Then turn on the light without allowing the observer sufficient time to spell the writing.

In spite of this, he will in most cases read the entire phrase, without hesitation or difficulty.

He has restored what was missing, or corrected what was at fault.

Now, ask him what letters he is certain he saw, and you will find he will tell you an omitted or altered letter as well as a letter actually written.

The observer then thinks he sees in broad light a letter which is not there, if that letter, in virtue of the general sense, ought to appear in the phrase. But you can go further, and vary the experiment.

Suppose we write the word "tumult" correctly. After doing so, to direct the memory of the observer into a certain trend of recollection, call out in his ear, during the short time the light is turned on, another word of different meaning, for example, the word "railway."

The observer will read "tunnel"; that is to say, a word, the graphical outline of which is like that of the written word, but connected in sense with the order of recollection called up.

In this mistake in reading, as in the spontaneous correction of the previous experiment, we see very clearly that perception is always the fulfilment of guesswork.

It is the direction of this work that we are concerned to determine.

According to the popular idea, perception has a completely speculative interest: it is pure knowledge. Therein lies the fundamental mistake.

Notice first of all how much more probable it is, a priori, that the work of perception, just as any other natural and spontaneous work, should have a utilitarian signification.

"Life," says Mr Bergson with justice, "is the acceptance from objects of nothing but the useful impression, with the response of the appropriate reactions." ("Laughter", page 154.)

And this view receives striking objective confirmation if, with the author of "Matter and Memory", we follow the progress of the perceptive functions along the animal series from the protoplasm to the higher vertebrates; or if, with him, we analyse the task of the body, and discover that the nervous system is manifested in its very structure as, before all, an instrument of action. Have we not already besides proof of this in the fact that each of us always appears in his own eyes to occupy the centre of the world he perceives?

The "Riquet" of Anatole France voices Mr Bergson's view: "I am always in the centre of everything, and men and beasts and things, for or against me, range themselves around."

But direct analysis leads us still more plainly to the same conclusion.

Let us take the perception of bodies. It is easy to show—and I regret that I cannot here reproduce Mr Bergson's masterly demonstration—that the division of matter into distinct objects with sharp outlines is produced by a selection of images which is completely relative to our practical needs.

"The distinct outlines which we assign to an object, and which bestow upon it its individuality, are nothing but the graph of a certain kind of influence which we should be able to employ at a certain point in space: it is the plan of our future actions which is submitted to our eyes, as in a mirror, when we perceive the surfaces and edges of things. Remove this action, and in consequence the high roads which it makes for itself in advance by perception, in the web of reality, and the individuality of the body will be reabsorbed in the universal interaction which is without doubt reality itself." Which is tantamount to saying that "rough bodies are cut in the material of nature by a perception of which the scissors follow, in some sort, the dotted line along which the action would pass." ("Creative Evolution", page 12.)

Bodies independent of common experience do not then appear, to an attentive criticism, as veritable realities which would have an existence in themselves. They are only centres of co-ordination for our actions. Or, if you prefer it, "our needs are so many shafts of light which, when played upon the continuity of perceptible qualities, produce in them the outline of distinct bodies." ("Matter and Memory", page 220.) Does not science too, after its own fashion, resolve the atom into a centre of intersecting relations, which finally extend by degrees to the entire universe in an indissoluble interpenetration?

A qualitative continuity, imperceptibly shaded off, over which pass quivers that here and there converge, is the image by which we are forced to recognise a superior degree of reality.

But is this perceptible material, this qualitative continuity, the pure fact in matter? Not yet. Perception, we said just now, is always in reality complicated by memory. There is more truth in this than we had seen. Reality is not a motionless spectrum, extending to our view its infinite shades; it might rather be termed a leaping flame in the spectrum. All is in passage, in process of becoming.

On this flux consciousness concentrates at long intervals, each time condensing into one "quality" an immense period of the inner history of things. "In just this way the thousand successive positions of a runner contract into one single symbolic attitude, which our eye perceives, which art reproduces, and which becomes for everybody the representation of a man running." ("Matter and Memory", page 233.)

In the same way again, a red light, continuing one second, embodies such a large number of elementary pulsations that it would take 25,000 years of our time to see its distinct passage. From here springs the subjectivity of our perception. The different qualities correspond, roughly speaking, to the different rhythms of contraction or dilution, to the different degrees of inner tension in the perceiving consciousness.

Pushing the case to its limits, and imagining a complete expansion, matter would resolve into colourless disturbances, and become the "pure matter" of the natural philosopher.

Let us now unite in one single continuity the different periods of the preceding dialectic. Vibration, qualities, and bodies are none of them reality by themselves; but all the same they are part of reality. And absolute reality would be the whole of these degrees and moments, and many others as well, no doubt. Or rather, to secure absolute intuition of matter, we should have on the one hand to get rid of all that our practical needs have constructed, restore on the other all the effective tendencies they have extinguished, follow the complete scale of qualitative concentrations and dilutions, and pass, by a kind of sympathy, into the incessantly moving play of all the possible innumerable contractions or resolutions; with the result that in the end we should succeed, by a simultaneous view as it were, in grasping, according to their infinitely various modes, the phases of this matter which, though at present latent, admit of "perception."

Thus, in the case before us, absolute knowledge is found to be the result of integral experience; and though we cannot attain the term, we see at any rate in what direction we should have to work to reach it.

Now it must be stated that our realisable knowledge is at every moment partial and limited rather than exterior and relative, for our effective perception is related to matter in itself as the part to the whole. Our least perceptions are actually based on pure perception, and "we are aware of the elementary disturbances which constitute matter, in the perceptible quality in which they suffer contraction, as we are aware of the beating of our heart in the general feeling that we have of living." ("The Journal of Philosophy, Psychology, and Scientific Methods", 7th July 1910.)

But the preoccupation of practical action, coming between reality and ourselves, produces the fragmentary world of common-sense, much as an absorbing medium resolves into separate