TERRESTRIAL PHENOMENA. 29 



from the centre, in the cases of fire and air, and downwards 

 towards the centre, in the cases of earth and water, and the 

 existence of a fifth element, sether, having a circular motion 

 and existing at a great distance from us, vitiated many of 

 his results, and sometimes caused him much trouble when 

 attempting to show that his results were in accord with the 

 phenomena. Examples of this will be seen in his explana- 

 tions of falling stars and thunderbolts. 



Many of the problems which Aristotle sought to solve 

 would require the use of instruments which he did not 

 possess, and, without the aid of these, he could scarcely do 

 otherwise than fail. His explanations of celestial, atmo- 

 spheric, and terrestrial phenomena are often of a fanciful 

 nature and constitute some of his least valuable w^ork. Some 

 of the phenomena he records are very interesting, as already 

 stated, and, in the following description, his records of this 

 kind will be discussed after his opinions on the causes to 

 which the phenomena were due have been considered. As 

 far as possible, the celestial phenomena will be discussed first, 

 then the atmospheric, and, finally, the terrestrial. 



According to Aristotle, there is but one Kosmos or 

 Universe; it is spherical in form and finite in magnitude; it 

 includes all matter, and outside it there is neither place nor 

 time ; it was not generated, neither can it be destroyed ; it 

 rotates to the right, and its rotation is uniform. This is an 

 epitomized statement of Aristotle's views on the Kosmos, as 

 set out at great length in his De Ccelo, i. cc. 5-12, ii. cc. 1, 

 4, 5, and 6. Being in the form of a sphere, the Kosmos was 

 capable of rotating so as to occupy the same position and 

 space at all times. This form was assigned to it because 

 the Kosmos is necessarily perfect, and the only perfect 

 geometrical figure is the sphere, which Aristotle considered 

 to be representative of perfection, uniformity, and eternity. 

 He decided that the Kosmos was finite for several reasons, 

 one being that there could not be an infinite square, sphere, 

 or other geometrical figure,* and he defined the infinite to 

 be that of which, taking any part whatever for consideration, 

 there is always something beyond, for it is not that beyond 

 which nothing exists.! He says that the infinite exists in 

 ^vvaixi^, i.e., potentially, but this must not be understood to 

 mean that the infinite will exist, in the same way as it may 

 be said that if a material is capable of existing in the form 



■■'■ De Ccelo, i. c. 5, 2726. f Physics, iii. c. 6, ss. 7 and 8. 



