556 PSYCHOLOGY OF PRESTIDIGITATION. 



I. 



Mr. James Sally, the einiueiit English i)sychologist, has made a 

 distinction with regard to the illusions of the senses which presents 

 real i)hilosophical value. The ilhisions of the senses, he says, should 

 be divided into two categories, the active illusions and the passive 

 illusions. The passive illusions are general; they are those M^hich are 

 experienced under the same conditions by all individuals; they are 

 inherent in our psychic organization, and no one can es(!ape them. It 

 is a law that we see objects in a perpeudicuhir position, notwithstand- 

 ing the fact that their image is reversed upon the retina of the eye. A 

 stick plunged into the water has to us the appearance of being- broken. 

 From these errors, common to all, we must distinguish those Mr. Sully 

 calls active, those that are productions of the spontaneous activity of 

 the mind ; these remain individual unless they take the epidemical form. 

 They are the result of our temx)erament, the state of our mind and our 

 belief. Hence it is by an active illusion that while awaiting a person 

 on the roadway we fancy we recognize him in a person approaching" in 

 the distance. 



Without going so far as to say that all belonging to the active illu- 

 sions present a certain gravity, it must not be forgotten that it is 

 illusions of this kind and not the others that are near relations to the 

 hallucinations of madness. 



Unquestionably illusions of prestidigitation form a jiart of the pas- 

 sive illusions, and, as it were, normal, which dominate all well-consti- 

 tuted persons. Subsequent analysis will contirm this aflirnuition, in 

 showing on which precise point the error of the senses bears. Mr. 

 Max Dessoir has discusssed this question a propos of an interesting 

 experience. He supposes an illusionist taking an orange, and after 

 having shown it to those around him, throws it up into the air and 

 then catches it in his hand as it descends. He repeats this i^erform- 

 ance once, twice, and the third time, after having placed the orange in 

 his pocket without the knowledge of those looking on, he makes a pre- 

 tense of again throwing it up in the air. Mr. Dessoir thinks, and we 

 think with him, that many of those present misled by this action would 

 believe they again saw the orange being tossed into the air as on the 

 two other occasions, and would be greatly astonished at not seeing it 

 descend as they had reason to believe it would. What is the nature of 

 the illusion in such a case! What name umst be given to it! To see 

 an object in a place where in reality it is not, is an hallucination. Mr. 

 Dessoir has good reason to discard this injudicious interpretation. The 

 word hallucination, as we have frequently observed, must be used only 

 with reference to an illusion that can have no explanation in exterior 

 things; it is a disorder of the senses, not a normal error. If the spec- 

 tators believe they see the orange, then they yield, as we will explain, 

 to a pretense on the part of the conjurer; they give themselves up to 



