503 HISTORY OF PHILOSOPHY. 



to all facts, that it may consider those facts, and which pretended io 

 determine all that existed from the ideas which the reason forms on 

 what ought to exist. Like his predecessors in antiquity, he went 

 back to the generation of the universe. But they enquired, what 

 that generation was? lie, whether there really had ever been any ? 

 Why that which did not exist commenced its existence? How that 

 which does exist suffers change ? How came into operation the 

 transition from non-existence to existence, from one sort of existence 

 to another ? He consulted the explanations of his predecessors, but 

 with them he was not satisfied. 



He then endeavoured himself to penetrate the mysterious darkness 

 todiscover the reason of existence, the manner of it, and its changes. 

 From the apophthegm, "Nothing comes of nothing," he deduced 

 this consequence, that " one thing could not arise out of another ; " 

 for that in the second which differed from the first and was now, 

 could not then have wherewith from which to date its origin. One 

 thing could not produce another, which was either dissimilar or merely 

 analogous to itself. It could only reproduce itself identically. Hence 

 resulted this general consequence, that all which is, is eternal, un- 

 changeable, and must remain so. As the things which exist can never 

 change, so they cannot be different from each other ; we cannot there- 

 fore conceive dissimilar beings : it follows, therefore, that being is 

 unique. Thought, according to Xenophanes, was the only real, 

 constant, and unchangeable substance. 



In his notions on natural theology he was elevated far above the 

 superstitions of the vulgar. " There is but one God," said he, " who 

 is perfect : we cannot conceive him under a human form, nor can 

 the ordinary limitations of space and motion have any affinity with 

 him." He is vulgarly supposed to have worshipped the Deity under 

 the form of a sphere : but doubtless he only used this mode of ex- 

 plaining his ideas of perfection and unity, for the idea of the material 

 shape which the Deity is thus supposed to assume is not countenanced 

 by any part of his doctrine. 



After having pursued the account of Xenophanes's system thus 

 far, we are surprised to find him treat of a physical cosmology in 

 which he distinguishes four different elements, speculates on the laws 

 of nature, and affirms (though this last opinion rests on doubtful au- 

 thority) that all things come from the earth, and return to it, and that 

 the body of man is composed of earth and water. The difficulty, 

 however, vanishes on a little further consideration. He distinguished 

 the physical from the intellectual world, and entirely separated the 

 one from the other, making them the objects of two distinct sciences. 

 To the latter alone he allowed a real existence, in which he recog- 

 nised a permanent and unique substance. To the former, the mate- 

 rial universe, he gave a phenomenal value, subordinate and inferior 

 to the world of reason. 



Parmenides, the confidant of Xenophanes, built up the edifice 

 whose foundation he had laid, developing his ideas, and giving his 

 opinions a systematic form. From him emanated the first distinct 

 theory on human knowledge ; it w characterized by great precision 



