Poe set this method to work in many of his poems and 
stories. But it is most obvious in his invention of the detective 
story in which Dupin, his sleuth, is an artist-aesthete who 
solves crimes by a method of artistic perception. Not only is the 
detective story the great popular instance of working 
backwards from effect to cause, it is also the form in which the 
reader is deeply involved as co-author. Such is also the case in 
symbolist poetry whose completion of effect from moment to 
moment requires the reader to participate in the poetic process 
itself.

     It is a characteristic chiasmus that waits upon the 
utmost development of any process that the last phase shall 
show characteristics opposite to the early phases. A typical 
example of massive psychic chiasmus or reversal occurred when 
Western man fought the harder for individuality as he