THE CONSTITUTION OF MATTER. 555 



finality. Matter no more proceeds from extension than extension pro- 

 ceeds from matter. This simple remark suffices to settle the difficulty 

 of conceiving how the dimension of' objects results from a group of 

 dynamic points which have no dimension. Extension existing before 

 every thing else, it is quite clear that, when certain primal energies 

 come into union to give rise, through a thousand successive complica- 

 tions, to phenomena and to bodies, what they really produce is not the 

 appearance of extension, which is the mere shadow of reality, but it is 

 that collection of various and diverse activities which enable us to 

 describe and define phenomena and bodies. 



It is no longer a subject of doubt, in the minds of savants who have 

 got beyond experimentation, that extension is an image and a show 

 rather than an essential constituent property of bodies. The extension 

 of bodies is a phenomenon which takes its rise in the collision of force 

 with our minds. Charles de Remusat, so long ago as 1842, gave an 

 original and remarkable demonstration of this. He maintains that 

 force is the cause of extension, meaning by that that the sensation of 

 extension is a modification of our sensibility, occasioned by forces 

 analogous to those which produce sensations of a more complex kind. 

 When you experience an electric shock, you are struck. Percussion is 

 the sensation of contact, in other words, of impulsion by something 

 that has extension. Now, in this instance, Remusat says, the cause of 

 percussion, electricity, has no extension. Therefore, he adds, either 

 electricity is nothing, or else it is a force which affects us in a way that 

 may be compared to the effect of extension. So that a force, wanting 

 the usual appearances of extension, may produce the same effects on 

 us that a solid body in motion does. Within a few years a profound 

 metaphysician, Magy, has pointed out by new arguments that cor- 

 poreal extension is merely a show which springs from the internal 

 reaction of the soul against the impression made on the sensorium, and 

 which the soul translates to outward bodies, by a law analogous to 

 that which makes it localize in the separate organs of sense the im- 

 pression which it has nevertheless perceived only in the brain. Each 

 sensation of taste, smell, light, or sound, is a phenomenon of psycho- 

 logical reaction which occurs in the soul when it is teased with a cer- 

 tain degree of energy by nerve-action, which in its turn depends on an 

 outward action ; but there is no relation of resemblance between the 

 latter and the sensation it provokes. The ether, which, by its vibra- 

 tions in unison with the elements of our retina, produces sensations of 

 light in us, has in itself no luminosity. The proof of this is that two 

 rays of light meeting under certain conditions may annul each other, 

 and produce darkness. Now, Magy maintains that the subjectivity of 

 extension is of the same order with that of light. Extension in gen- 

 eral is explained by purely dynamic reasons, as readily as that par- 

 ticular extension is which serves as a kind of support for luminous 

 phenomena, which evidently result from vibrations of the unextended 



