4 KANT'S PRELIMINARY DISCUSSION 



have been employed to prevent the commencement of it 

 from moving through all the seasons, and comparing it 

 with the length of the year as determined in our day. 

 The object of this would be to see whether the year in 

 the most ancient times contained more or fewer days, or 

 hours, than it does now. In the former case the rapidity of 

 the axial rotation would be proved to have been lessened, 

 but in the second case increased, down to the present 

 time. In my sketch I shall not attempt to obtain light 

 on the subject by the aid of history. I find its record 

 so obscure and its accounts so unreliable, as regards the 

 question under consideration, that any theory which might 

 be devised on that basis to make it accord with the 

 principles of nature would probably seem to savour of 

 the imagination. I shall therefore keep directly to nature, 

 whose connections may distinctly indicate the proper result 

 and give occasion to turn the observations drawn from 

 history to the right side. 



The Earth turns unceasingly round its axis with a free 

 motion which, having been impressed upon it once for all 

 at the time of its formation, would continue thenceforth 

 unaltered for all infinite time and go on with the same 

 velocity and direction, did no impediments or external 

 causes exist to retard or to accelerate it. I proceed to 

 show that such an external cause actually exists, and 

 that it is really a cause which gradually diminishes the 

 motion of the earth and tends even to destroy its rotation, 

 in the course of immensely long periods. This event, 

 which is destined some day to happen, is so important 

 and wonderful that, although the fatal moment of its 

 occurrence is so far postponed that even the capability 

 of the earth to b'e inhabited and the duration of the 



