186 Professor Whewell on the 



I shall have to state some of the principles which are said to 

 apply to the questions now before us; they have been put for- 

 wards with great ingenuity by Mr. Ricardo and his followers; and 

 several curious speculations have been founded upon them, espe- 

 cially those connected with the influence of the manufacturing 

 skill of a country upon the influx of gold into it, and conse- 

 quently upon the general scale of prices. 



It will be seen, that besides the principles which I borrow 

 from Mr. Ricardo, I shall have to make several assumptions for 

 the sake of reducing the problems before us to calculation. It 

 will of course be understood that these assumptions are not in- 

 tended to be maintained as exactly, or even as approximately 

 true. Their use is to shew how the numerical examples which 

 serve as illustrations of the principles, may be properly and con- 

 sistently generalized and limited. But though these investigations 

 cannot pretend at present to much precision, it is hoped that 

 they may serve to shew, of what kind and how many are the 

 data on which the exact solution of such problems must depend: 

 and they may thus be of some use in directing future attention 

 with regard both to the laws and the quantities involved in these 

 difficult questions. 



I suppose the Commerce of different countries to take place 

 free from all prohibitions, duties, drawbacks, &c. This simplifi- 

 cation appears to be the easiest mode of undertaking the inves- 

 tigation at first. I may, perhaps, on some other occasion con- 

 sider similar problems with the additional conditions which such 

 restrictions introduce. 



On this supposition we shall assume the following principles. 



