The Collaborative International Dictionary of English v.0.48:

Nescience \Nes"cience\, n. [L. nescientia, fr. nesciens, p. pr.
   of nescire not to know; ne not + scire to know.]
   Want of knowledge; ignorance; agnosticism.
   [1913 Webster]

         God fetched it about for me, in that absence and
         nescience of mine.                       --Bp. Hall.
   [1913 Webster]

WordNet (r) 3.0 (2006):

nescience
    n 1: ignorance (especially of orthodox beliefs) [syn:
         ignorantness, nescience, unknowing, unknowingness]