DWARFS AND GIANTS. 767 



categories of mental faculties. Ansemia is likewise a condition of fre- 

 quent occurrence. At later periods, as Luys says, the optic thalami 

 are the seats of degenerations which show that there have been fre- 

 quent perturbations of the circulation. He is very strong in his con- 

 viction that there are secondary changes, which are the cause of the 

 transformation of psycho-sensorial hallucinations into those which 

 Baillarger designated psychic. In my opinion, they are the cause of 

 the hallucination becoming a delusion, and, indeed, between a psychic 

 hallucination and a delusion there is very little difference. The former 

 can not exist without the involvement of the intellect. 



-++- 



DWARFS AND GIANTS.* 



By M. DELBCEUF. 



A BELGIAN philosopher, M. Stas, declared, two years ago, that 

 " no science to which measure, weight, and calculation are not 

 applicable can be considered an exact science ; it is only a mass of 

 unconnected observations, or of simple mental conceptions." I agree 

 to this without reserve. Undoubtedly, vain imaginations and crude 

 theories, which have form without solidity, should be banished from 

 science ; but it does not follow that we must define science as a col- 

 lection of weights and measures, and calculations upon them, or as 

 consisting of combinations of algebraic formulas from which other 

 formulas may be deduced. These matters of weight, measure, and 

 calculation must have some synthesis or useful purpose in view. They 

 should throw light upon some law, and that a law which is an idea, or 

 which is susceptible of being converted into an idea. It is the philo- 

 sophic thought penetrating them that gives interest to the statistical 

 labors of Quetelet. The cry of the positivists of the day is for " facts ! " 

 To that I oppose another cry : " Ideas ! give us ideas ! " A fact with- 

 out an idea is a body without a soul, a useless incumbrance to the 

 memory. I come to the defense of speculation. While I view with 

 impatience volumes of figures, operations, and formulas, of which the 

 signification and bearing can not be perceived, I am inclined to be 

 grateful to the man who throws out a new idea, though it be a thou- 

 sand times false. There is always more to be learned from the thinker 

 who talks nonsense logically than from the observer who does not 

 reason at all. From nothing, nothing can come, but error may bring 

 forth the truth at the price of its own death. 



Laying aside these generalities, let us consider an example of the 



* From an address before the Royal Academy of Belgium. Translated for " The 

 Popular Science Monthly." 



