PEEFACE TO THE PEESENT EDITION. 



SINCE the 24th of April, 1832, when the last of the accom- 

 panying Letters by Sir David Brewster to Sir Walter 

 Scott was written, many circumstances have occurred to 

 extend the importance of that wide and comprehensive 

 subject which Sir David has embraced under the name of 

 Natural Magic ; for though education, intelligence, and 

 scientific discovery have been advancing with rapid strides, 

 credulity has not been, and does not seem ever likely to 

 be, wholly eradicated by their means, while the ingenious 

 have been armed with immense and varied additional 

 elements to favour deception if they shall choose to employ 

 them for that purpose. It has appeared to the editor of 

 the present edition, therefore, of the highest importance 

 to give the work the benefit of that profounder interest 

 which must arise from a consideration of the physical and 

 metaphysical existence or being of man the union of 

 these two conditions of his being in their action, through 

 the faculties or powers of human perception and verifica- 

 tion, and also from a consideration of the range of natural 

 possibility ; for by a proper knowledge of these mankind 

 will be better aware of the extent of their liability to be 

 deceived, and of the means of verification and correction 

 at their command, as well as of the mode in which their 

 liability to deception ought to be guarded against or 



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