THE BELFAST ADDRESS. 159 



blood which the heart diffuses, ' the oil of the lamp of 

 life,' deducing all animal motions from the combustion 

 of this oil, as the motions of a steam-engine are deduced 

 from the combustion of its coal. As the matter stands, 

 however, and considering the circumstances of the time, 

 the boldness, clearness, and precision, with which Des- 

 cartes grasped the problem of vital dynamics constitute 

 a marvellous illustration of intellectual power. 1 



During the Middle Ages the doctrine of atoms 

 had to all appearance vanished from discussion. It 

 probably held its ground among sober-minded and 

 thoughtful men, though neither the church nor the 

 world was prepared to hear of it with tolerance. Once, 

 in the year 1348, it received distinct expression. But 

 retractation by compulsion immediately followed ; and, 

 thus discouraged, it slumbered till the seventeenth 

 century, when it was revived by a contemporary and 

 friend of Hobbes of Malmesbury, the orthodox Catholic 

 provost of Digne, Grassendi. But, before stating his 

 relation to the Epicurean doctrine, it will be well to 

 say a few words on the effect, as regards science, of the 

 general introduction of monotheism among European 

 nations. 



6 Were men,' says Hume, * led into the apprehension 

 of invisible intelligent power by contemplation of the 

 works of Nature, they could never possibly entertain 

 any conception but of one single Being, who bestowed 

 existence and order on this vast machine, and adjusted 

 all its parts to one regular system.' Eeferring to the 

 condition of the heathen, who sees a god behind every 

 natural event, thus peopling the world with thousands 

 of beings whose caprices are incalculable, Lange shows 

 the impossibility of any compromise between such 



1 See Huxley's admirable ' Essay on Descartes.' Lay Sermons,' 

 pp. 364, 3G5. 



