jiS THE PHILOSOPHY 



ing and deficcatlon of their conftituent parts. No art, no medicine, 

 can retard the operations of Nature. It is, therefore, the wifdom 

 and the duty of every human being to fail down the irrefiftible cur- 

 rent of Nature with all poflible tranquillity and refignation. Life,' 

 whether fhorc or long, whether fortunate or unfortunate, when the 

 fatal period arrives, is of little confequence to the individual. Socie- 

 ty, knowledge, virtue, and benevolence, are our only rational en- 

 joyments, and ought to be cultivated with diligence. 



With regard to animals in general, the adual duration of their 

 lives is very different. But the comparative fhortnefs or length of 

 life, in particular animals, probably depends on the quicknefs or 

 flownefs of the ideas which pafs in their minds, or of the impref- 

 fions made upon their fenfes. A rapid fucceflion of ideas or impref- 

 fions makes time feem proportionally long. There is likewife a con- 

 nedlion betvpeen the quicknefs and flownefs of ideas, and the circu- 

 lation of the blood. A man whofe pulfe is flow and fluggifli, is ge- 

 nerally dull and phlegmatic. Raife this fame man's pulfe with wine, 

 or any other exhilarating ftimulus, and you immediately quicken his 

 fenfations, as well as the train of his ideas. In all young animals, 

 the circulation of the blood is much more rapid than after they have 

 acquired their full growth. Young animals, accordingly, are frolick- 

 fome, vivacious, and happy. But, when their growth is completed, 

 the motion of the blood is flower, and their manners, of courfe, are 

 more fedate, gloomy, and penfive. Another circumfl:ance merits at- 

 tention. The circulation of the blood is flower or quicker in pro- 

 portion to the magnitude of animals. In large animals, fuch as man 

 and quadrupeds, the blood moves flowly, and the fuccefl^ion of their 

 ideas is proportionally flow. In the more minute kinds, as mice^ 

 fmall birds, fquirrels, &c. the circulation is fo rapid that the pulfes 

 of their arteries cannot be counted. Now, animals of this defcrip- 

 tion afl;onifl\ us with the quicknefs of their movements, the vivacity 



of 



