Heredity of the Sensorial Qualities. 35 



CHAPTER II. 



HEREDITY OF THE SENSORIAL QUALITIES. 



PERCEPTION is a fact of mixed nature, at once physiological and 

 mental ; it is begun in the organs, is perfected in the consciousness. 

 The soundness of the common opinion which regards our sensa- 

 tions as simple, irreducible, ultimate phenomena, by means of which 

 we know the material world as it is, is extremely doubtful. Setting 

 aside the discussion of this broad question, it is only necessary 

 to say that, taking for their basis physical and physiological dis- 

 coveries, recent works on psychology notably those of Bain and 

 Herbert Spencer in England, of Helmholtz and Wundt in Ger- 

 many, and of Taine in France have shown that sensations 

 supposed to be simple must be dealt with, as chemistry, at its rise, 

 dealt with bodies, also supposed to be simple. These psycho- 

 logists v have shown that neither colours, nor sounds, nor heat, 

 probably, indeed, none of the qualities of the external world, at all 

 resemble the ideas vulgarly entertained with regard to them ; that 

 perception is a state of consciousness that corresponds in us to 

 realities external to ourselves, but which does not resemble them : 

 so that this totality of attributes which we call the external world, 

 and which, by a universal illusion, we think we see as it is in 

 reality, is to a great extent the product of our own mind a creation 

 of which the external world furnishes only the raw material, which 

 our senses then, after their own fashion, work up and complete. 



Though we cannot have the slightest hesitation in choosing 

 between these recent theories and the current opinion in regard to 

 the perception of external objects, between that of the Scotch 

 school and of the sensus communis whose least defect is that it 

 explains nothing ; yet, so far as the subject of heredity is concerned, 

 the question has no interest Whether the material world is per- 

 ceived immediately as it is, or otherwise than as it is, by a 

 synthesis of consciousness, matters not at all. The only problem 

 we have to solve is whether the perceptive faculties, the modes of 

 sensorial activity, are subject to heredity. 



We will observe, in the first place, that, as regards specific quali- 

 ties, the reply admits of no doubt If we examine the animal 



