PROGRESS OF HUMAN KNOWLEDGE. 5 



language in philosophy and science, from the thraldom 

 of which we are hardly yet emancipated. I need not 

 speak of the tyranny which mere phrases often exercise 

 over the understanding, even of the wisest. It is one 

 of the best marks of present progress that, in natural 

 science at least, so much has been done to rescue the 

 mind from this tyranny of words, the coinage of older 

 times and imperfect knowledge. Much, however, 

 remains to be done in reforming and settling the lan- 

 guage even of the purest sciences. Their vocabulary 

 has of necessity been much enlarged by their very 

 growth, while the fact that almost all are in progressive 

 or transitional state, renders this vocabulary in many 

 cases conventional only, awaiting those changes which 

 more perfect knowledge will require. Chemistry 

 especially is in this condition, with the embarrassment 

 . of four or five rival nomenclatures to express the same 

 existing facts. 



The release from the bondage of old opinions is 

 still more marked than the changes of language. An- 

 cient authors are now quoted, not as authorities for 

 truth, but as indicating those earlier efforts to attain it, 

 which form one curious page in the/ history of mankind. 

 We read the ' Timseus ' of Plato as a tissue of strange 

 hypotheses, utterly wanting in the elements of proof. We 

 have a more faithful interpreter of nature in Aristotle (rr\s 

 <bv(rea)$ ypa^arsu^), eminent far above his age as an acute 

 and zealous observer, but not recognised as such during 

 the darkness of the mediaeval centuries. The scholastic 

 philosophy of that period embraced only the worser 

 part of the great works he has bequeathed to posterity. 



