SEVENTEENTH AND EIGHTEENTH CENTURIES 139 



what in many respects was a sound criticism, particularly of Aristoteleanism, 

 the weak points of which he brought out very clearly. In his writings he 

 closely examines Aristotle's theory of the relation of form to reality. Simi- 

 larly, he rejects the theory of the four elements, for, said he, fire is not an 

 element at all. Again, when Aristotle believes the fertilizing property of the 

 sperm to be due to its heat, van Helmont satirically asks how it is that the 

 cold-blooded fishes are more fertile than any warm-blooded animal. How- 

 ever, it proves here, as often, to be easier to destroy than to build up; van 

 Helmont's own theories cannot compete with Aristoteleanism at least in 

 clearness and consistency. This, indeed, is due partly to the peculiar mystical 

 principles on which he bases his views, and partly to his lack of stylistic 

 ability; his writings are extremely obscure and difficult to read. His concep- 

 tion of nature, like that of Paracelsus, is chemical, with a strong dose of 

 mysticism, which belonged to chemistry at that time. 



Van Helmont' s fermentation theory 

 The "fermentation process" plays an important part in his theories on nat- 

 ural phenomena; he had thoroughly studied this phenomenon and had shown 

 that fermenting must produces a kind of air which is identical with that given 

 off by burning charcoal and that which sometimes renders the air of caves 

 irrespirable. For this element he invented the name of gas, a word which has 

 since been accepted by science. He distinguished several kinds of gas, of 

 which, however, only the above-mentioned "gas sylvestre," or what we 

 call carbon dioxide, has been fully described. According to him, digestion 

 and every kind of conversion of substance in general are due to ferments. 

 The many different processes of fermentation which he thought he had dis- 

 covered in the human body were for the most part mere creations of his 

 fancy, but he had certain ideas which were to prove to be correct, as when 

 he points out the part played by acid in the cavity of the stomach in the 

 digestive process, and shows that the undue acidity of the digestive juices is 

 neutralized by the gall. He was not content with merely establishing facts of 

 this kind, however; like Paracelsus, he sought to get on the tracks of life 

 itself and, like him too, saw its innermost essence personified in an archeus, 

 which is situated in the region of the stomach and controls a number of 

 subsidiary archei in the other parts of the body. This central archeus, however, 

 regulates only the material conversion in the body and exists in various 

 forms in all beings; man has, besides his immortal soul, "intellectus," which 

 makes the soul participate in blessedness and would wholly control the body 

 had not the Fall intervened. After the Fall man received a lower soul, "ratio," 

 which makes it bound to earth and liable to its impulses, and finally to 

 death. Beings in the universe have the power of reacting upon one another 

 by a kind of force operating at a distance which he calls "bias" ; in particular 

 the bias proceeding from the heavenly bodies has remarkable properties, but 



