AND ITS SELF-CONSERVATION". 125 



A striking example of the absolute relativity of our 

 knowledge of motion is given in Clerk MaxwelFs admira- 

 ble little treatise on " Matter and Motion" (p. 36). He 

 says: " If, when referred to a certain point, the body ap- 

 pears to be moving northward with diminishing velocity, 

 we have only to refer it to another point moving north- 

 ward with a uniform velocity greater than that of the 

 body, and it will appear to be moving southward with 

 increasing velocity." 



We may, in short, heartily agree with the same author 

 when he declares it to be "unscientific to distinguish 

 between rest and motion, as between two different states 

 of a body in itself, since it is impossible to speak of a 

 body being at rest or in motion, except with reference, 

 expressed or implied, to some other body." 



It is assuredly "unscientific," not to say unphilo- 

 sophic, to attempt to set up a distinction in thought 

 where it is "impossible," even absolutely impossible, to 

 discover any distinction in fact. 



It would seem, then, that there is a possible contra- 

 diction involved in the conception that all our knowledge 

 of motion is relative in its nature. It would seem that, 

 so far as we have knowledge at all, such knowledge 

 must belong to us as a phase of our own consciousness. So 

 much, at least, we may fairly be allowed to know abso- 

 lutely. And further, we know, by an application of the 

 law of contradiction which, we have seen, is also to 

 be regarded as one phase of the larger law of con- 

 sistency that the only space we can truly think ; that 

 is, the only space we can ever know, in any rational 

 sense of the term is, in its very nature, absolutely 

 unlimited. We know absolutely, also, that, as there are 



