PSYCHOLOGY OF PRESTIDIGITATION 



By Alfred Binet. 



Everyone of iis, whether aware of it or not, has experienced ilhisions 

 of the senses; they do not always tell the truth. The eye, the ear, 

 deceive us, and even the liand, that Ave instinctively extend to test the 

 evidence of our other senses, has often played us false, though, to speak 

 more accurately, it is the mind and not the senses that is at fault. 

 The senses make known but one thing, the sensations. The eye merely 

 communicates the different shades of light or color; the hand, sensa- 

 tions of contact and movement. The mind interprets these sensations, 

 draws conclusions, and with these conclusions constructs exterior 

 objects endowed with numberless properties. When we say this is a 

 chair, a table, a dog, a house, we not only indicate what the eye has 

 perceived, but we reason it out. Y^et if this automatic and rapid 

 reasoning be at fault we have had an illusion of the senses. 



Prestidigitation is an art which has in view a singular aim, that of 

 seeking out and developing all iniluences which could lead us to be 

 deceived in what we see. A person witnessing experiments in presti- 

 digitation and understanding nothing of the means employed is easily 

 made to believe that he sees an object in one part of the room when it 

 is really elsewhere; he sees that which does not exist and sees not that 

 which really does exist. 



One can readily understand the interest of the psychologist in the 

 study of the means employed to produce these illusions, for it enlight- 

 ens us as to the process by which the mind perceives exterior objects, 

 and makes known likewise the weak points of our knowledge. Before 

 entering into the details of our analysis it may be well to determine by 

 certain general considerations the nature of the error produced by the 

 art of the prestidigitator.^ 



'Translated from Eevue des Denx Mondes, October 15, 1894. 



-We have borrowed the principal elements of this study from the old works of 

 Jacques Ozanan, Guyot, Decremps. Ponsiu, and from the more recent books of Robert 

 Houdin. Some authors, Mr. James Sully (Illusions des Sens et de I'Esprit) and Mr. 

 Max Dessoir (Open Court, 1893), have treated the question from a psychological 

 point of view, and we have borrowed from them useful indications. We have above 

 all tried to give the reader a clear idea of the performance of these tricks by con- 

 sulting professionals and recjuesting them to execute before us, in different condi- 

 ti<ms, tricks in which they very obligingly showed us that which they are in the 

 habit of carefully concealing. We will cite with pleasure among these benevolent 



coadjutors Messrs. Aruould, Dickson, Melies, Pierre, and Raynaly. 



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