incapableness

from WordNet (r) 3.0 (2006)

incapableness
    n 1: lack of potential for development [syn: {incapability},
         {incapableness}] [ant: {capability}, {capableness},
         {potentiality}]
    2: the quality of not being capable -- physically or
       intellectually or legally [syn: {incapability},
       {incapableness}] [ant: {capability}, {capableness}]

from The Collaborative International Dictionary of English v.0.48

Incapableness \In*ca"pa*ble*ness\, n.
   The quality or state of being incapable; incapability.
   [1913 Webster]