FLORENTINO AMEGHINO 307 



ficial, whatever conclusions it leads to. In this field he stood forth as 

 the chief exponent of doctrines maintained against strong and wide- 

 spread opposition, forced into recognition and partial acceptance by the 

 sheer vigor and energy with which he defended them, and the learning 

 and skill with which he marshalled a tremendous array of evidence in 

 their support. I, who disbelieve these views and have taken some share 

 in combating them, can well afford to honor the ability and industry 

 with which they were defended. Heterodoxy is of the life of scientific 

 doctrine, the surest indication of its vigor and progressiveness. Only 

 in decadence will our theories degenerate into a " body of geologic 

 dogma," admitted to universal belief with universal indifference. 



