Ch. ii. and the Mode of their Operation. 19 



trograde and progressive movements, with respect 

 to happiness, are repeated. 



This sort of oscillation will not probably be ob- 

 vious to common view ; and it may be difficult even 

 for the most attentive observer to calculate its 

 periods. Yet that, in the generality of old states, 

 some alternation of this kind does exist though in 

 a much less marked, and in a much more irregular 

 manner, than I have described it, no reflecting 

 man, who considers the subject deeply, can well 

 doubt. 



One principal reason why this oscillation has 

 been less remarked, and less decidedly confirmed 

 by experience than might naturally be expected, 

 is, that the histories of mankind which we possess 

 are, in general, histories only of the higher classes. 

 We have not many accounts that can be depended 

 upon, of the manners and customs of that part of 

 mankind, where these retrograde and progressive 

 movements chiefly take place. A satisfactory 

 history of this kind, of one people and of one pe- 

 riod, would require the constant and minute at- 

 tention of many observing minds in local and ge- 

 neral remarks on the state of the lower classes of 

 society, and the causes that influenced it; and, to 

 draw accurate inferences upon this subject, a suc- 

 cession of such historians for some centuries would 

 be necessary. This branch of statistical know- 

 ledge has, of late years, been attended to in some 

 countries,* and we may promise ourselves a 



* The judicious questions which Sir John Sinclair circulated 

 in Scotland, and the valuable accounts which he has collected in 



c 2 



