188 Experimental Philosophy. [Lecture 13. 



to the necessity of the eye, otherwise the rays will 

 not converge at the proper point. 



I cannot quit this subject without noticing the 

 gross stupidity of the atheist. Can any persons 

 in their senses conceive that so nice, so exquisite 

 an organ as the eye should be formed by chance ! 

 That by chance the humours should be disposed 

 with the most perfect mathematical precision, 

 so that a mistake to the breadth of a hair would 

 be sufficient to defeat the purpose of vision ! Yet 

 these are the men, my young friends, who without 

 understanding any principle of any one science, 

 have the impudence to call themselves philo- 

 sophers* ! though in what their philosophy can 

 consist, would require more than Newton pos- 

 sessed to be able to discover. 



There is reason to believe, that the use of 

 convex glasses, both as burning glasses and mag- 

 nifiers, was not unknown to the antients ; and, 

 in the twelfth century, Alhazen, an Arabic philo- 

 sopher, treated at some length of the magnifying 

 power of these glasses. He was followed by our 



* Why they have chosen to adopt this name no man 

 can possibly devise. They might as well have called them- 

 selves architects, heralds, antiquarians, or by any other de- 

 nomination with which they have no connexion what- 

 ever. Ask any of these pretended philosophers why a 

 convex lens causes the rays of light to converge, or any 

 similar question, and you will soon see whether they have 

 any pretension to the name of philosophers, 



