Source : Webster's Revised Unabridged Dictionary (1913)

Incogitance \In*cog"i*tance\, Incogitancy \In*cog"i*tan*cy\, n.
   [L. incogitantia.]
   Want of thought, or of the power of thinking;
   thoughtlessness; unreasonableness.

         'T is folly and incogitancy to argue anything, one way
         or the other, from the designs of a sort of beings with
         whom we so little communicate.           --Glanvill.