\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.