52 ARISTOTLE. 



poetical composition in general, and is equally distin- 

 guished for precision and depth of thought. Those 

 on ethics and politics are also remarkable produc- 

 tions ; and although the former has been effectually 

 superseded by a more perfect system, the latter con- 

 tains much that is interesting even at the present day. 

 In his metaphysics, he expounds the doctrine of Be- 

 ing abstracted from Matter, and speaks of a First 

 Mover, — the life and intellect of the universe, eter- 

 nal and immutable, but neither omnipresent nor 

 omnipotent. When treating of physics, he does not 

 in general lay down rules a prion, but deduces them 

 from the observation and comparison of facts. This 

 being the case, we might expect that such of his 

 writings as relate to natural history should contain 

 much truth. 



He holds that all terrestrial bodies are composed 

 of four elements, — earth, water, air, and fire. Earth 

 and water are heavy, because they tend towards the 

 earth's centre ; while air and fire, which tend up- 

 wards, are light. 



Besides these four elements, he has admitted a 

 fifth, of which the celestial objects were composed, 

 and whose motion is always circular. He supposed 

 that there is above the air, under the concave part 

 of the moon, a sphere of fire to which all the flames 

 ascend, as the brooks and rivers flow into the ocean. 



He maintains that matter is infinitely divisible; 

 that the universe is full, and that there is no vacuum 

 in nature ; that the world is eternal ; that the sun, 

 wiiicli has always revolved as it does at present, will 

 for ever continue to do so ; and finally, that the ge- 

 nerations of men succeed each other without having 

 had a beginning or foreseeing an end. 



