He asserted that the fallibility of human beings means that they cannot obtain absolute certainty except in trivial cases where a statement is true by definition (e.g. tautologies such as "all bachelors are unmarried" or "all triangles have three corners").
Tvrdio je da, kako ljudi nisu nepogrešivi, ne mogu doći do apsolutne sigurnosti, osim u trivijalnim slučajevima kad je tvrdnja istinita po definiciji (npr. tautologije poput "svi neženje su neoženjeni" ili "svi trokuti imaju tri kuta").