You say, but with no touch of scorn, 
        Sweet-hearted, you, whose light-blue eyes 
        Are tender over drowning flies, 
    You tell me, doubt is Devil-born. 
    I know not: one indeed I knew 
        In many a subtle question versed, 
        Who touch'd a jarring lyre at first, 
    But ever strove to make it true: 
    Perplext in faith, but pure in deeds, 
       At last he beat his music out. 
       There lives more faith in honest doubt, 
   Believe me, than in half the creeds. 
 
   He fought his doubts and gather'd strength, 
       He would not make his judgment blind, 
       He faced the spectres of the mind 
   And laid them: thus he came at length 
 
   To find a stronger faith his own; 
       And Power was with him in the night, 
       Which makes the darkness and the light, 
   And dwells not in the light alone, 
 
   But in the darkness and the cloud, 
       As over Sinaï's peaks of old, 
       While Israel made their gods of gold, 
   Altho' the trumpet blew so loud.
Alfred Lord Tennyson
http://www.poemhunter.com/poem/in-memoriam-a-h-h-96-you-say-but-with-no-touch-o/