incogitancy

CIDE DICTIONARY

incogitancy, n. [L. incogitantia.].

 Lack of thought, or of the power of thinking; thoughtlessness; unreasonableness.  [1913 Webster]
"'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."  [1913 Webster]

ROGET THESAURUS

incogitancy

Incogitancy

N incogitancy, vacancy, inunderstanding, fatuity thoughtlessness, vacuity, couch potato, vegetable, vacant, unintellectual, unideal, unoccupied, unthinking, inconsiderate, thoughtless, mindless, no-brain, vacuous, absent, diverted, irrational narrow-minded, unthought of, undreamt 'of, unconsidered, off one's mind, incogitable, not to be thought of, absence d'esprit, pabulum pictura pascit inani.