IMPORTANCE OF DISCOVERING GENERAL TRUTHS. 193 



are sometimes as valuable as some others which yield 

 positive ones, because they enable us to form valuable 

 conclusions. The disproof of a false belief or super- 

 stition sometimes conduces as much to the progress of 

 civilisation and the well-being of mankind as the ascer- 

 tainment of a new truth. In important cases, even results 

 which only enable us to form a probable opinion are, in 

 the absence of more certain knowledge, of great value. 

 For instance, at present we know that the light of some 

 of the whitest and brightest of stars, such as Sirius, yields 

 only the spectrum of hydrogen, and it is therefore con- 

 sidered probable by some investigators that the other 

 elementary bodies formerly present have been decomposed 

 by the intense heat into that primal element ; and as none 

 of the heavenly bodies yield spectra of iodine, bromine, or 

 chlorine, it is further considered probable that of all the 

 elementary bodies those are the most easily decomposed 

 by heat. 



Special subjects occasionally acquire a temporary and 

 fictitious degree of importance in consequence of having 

 been neglected for a time and left behind in the stream of 

 human progress. By being thus neglected, they retard, 

 and ultimately stop, the progress of some of the more 

 advanced subjects, and their development thus becomes a 

 matter of necessity and importance. It is, however, not 

 the subjects themselves, but their development, that is 

 altered in importance. The intrinsic value of the subjects 

 remains the same, because both the quality and quantity 

 of the knowledge they contain is unaltered. 



