NOVUM ORGANUM 51 



while men derived but few from discussion and the con 

 clusions of reason. 



The industry of the alchemists has produced some effect, 

 by chance, however, and casualty, or from varying their ex 

 periments (as mechanics also do), and not from any regular 

 art or theory, the theory they have imagined rather tending 

 to disturb than to assist experiment. Those, too, who have 

 occupied themselves with natural magic (as they term it) 

 have made but few discoveries, and those of small import, 

 and bordering on imposture; for which reason, in the same 

 manner as we are cautioned by religion to show our faith 

 by our works, we may very properly apply the principle to 

 philosophy, and judge of it by its works, accounting that to 

 be futile which is unproductive, and still more so if, instead 

 of grapes and olives, it yield but the thistle and thorns of 

 dispute and contention. 



LXXIY. Other signs may be selected from the increase 

 and progress of particular systems of philosophy and the 

 sciences; for those which are founded on nature grow and 

 increase, while those which are founded on opinion change 

 and increase not. If, therefore, the theories we have men 

 tioned were not like plants, torn up by the roots, but grew 

 in the womb of nature, and were nourished by her, that 

 which for the last two thousand years has taken place would 

 never have happened, namely, that the sciences still con 

 tinue in their beaten track, and nearly stationary, without 

 having received any important increase, nay, having, on 

 the contrary, rather bloomed under the hands of their first 

 author, and then faded away. But we see that the case is 

 reversed in the mechanical arts, which are founded on na 

 ture and the light of experience, for they (as long as they 

 are popular) seem full of life, and uninterruptedly thrive and 



SCIENCE Vol. 22 3 



