Principles of Political Economy and Taxation. 157 



steady and universal in their operation, or to be of such para- 

 mount and predominant influence, that other principles, which 

 oppose and control them, may be neglected in comparison. 

 Some of them appear to be absolutely false in general, and others 

 to be inapplicable in almost all particular cases. Perhaps, how- 

 ever, to trace their consequences may be one of the most obvious 

 modes of verifying or correcting them. 



I proceed now to enumerate the Postulates which seem to 

 form the foundations of Mr. Ricardo's doctrines: and I shall 

 point out at the same time the manner in which they may be 

 mathematically expressed and treated. 



I. Postulate of Rent. 

 3. In the system now before us, agriculture is considered as 

 an employment of capital ; and the farmer as a person who lives 

 on his profits, and who can and will remove his capital to another 

 employment, if his profits can be so increased, or so prevented 

 from falling. Hence the farmer will not consent to make less than 

 the average rate of profits ; also, competition will not allow him 

 to make more: and therefore the excess of the produce of the land 

 above that amount which is necessary to realize such profits, will 

 be transferred to the landlord as rent. Hence, on these supposi- 

 tions, rent is the excess of the produce of capital employed on 

 land, above the produce of the same capital otherwise employed. 

 It is also supposed that there are soils of diiferent degrees »t 

 fertdity, which form a continuous decreasing series : and that the 

 lowest degree of fertility on which the cultivator can obtain a 

 living profit without paying rent, will be cultivated. 



It is also supposed that there are modes of employing, on the 

 same land, successive quantities on doses of capital, and that 



