THE PERCEPTION OF THINGS. 129 



ral point de repere is used in an enormous number, not only 

 of hypnotic hallucinations, but of hallucinations of the 

 insane. These latter are often unilateral ; that is, the patient 

 hears the voices always on one side of him, or sees the 

 figure only when a certain one of his eyes is open. In 

 many of these cases it has been distinctly proved that a 

 morbid irritation in the internal ear, or an opacity in the 

 humors of the eye, was the starting point of the current 

 which the patient's diseased acoustic or optical centres 

 clothed with their peculiar products in the way of ideas. 

 Hallncinations produced in this icay are 'illusions '; and M. 

 Binet's theory, that all hallucinations must start in the periphery, 

 may be called an attempt to reduce hallucination and illusion to 

 one physiological type, the type, namely, to which normal per- 

 ception belongs. In every case, according to M. Binet, 

 whether of perception, of hallucination, or of illusion, we 

 get the sensational vividness by means of a current from 

 the peripheral nerves. It may be a mere trace of a cur- 

 rent. But that trace is enough to kindle the maximal or 

 supra-ideational process so that the object perceived will 

 have the character of externality. What the nature of the 

 object shall be will depend wholly on the particular sys- 

 tem of paths in which the process is kindled. Part of the 

 thing in all cases comes from the sense-organ, the rest is 

 furnished by the mind. But we cannot by mirospection 

 distinguish between these parts ; and our only formula for 

 the result is that the brain has reacted on the impression in 

 the normal way. Just so in the dreams which we have 

 considered, and in the hallucinations of which M. Binet 

 tells, we can only say that the brain has reacted in an abnor- 

 mal way. 



M. Binet's theory accounts indeed for a multitude of cases ^ 

 hut certainly not for all. The prism does not always double 



baud, you will hear them say that they find uo difference between a real 

 flower which you show them and an imaginary flower which you tell 

 them is beside it. When told that one is imaginary and that they must 

 pick out the real one, they sometimes say the choice is impossible, and 

 sometimes they point to the imaginary flower. 



