 More recent philosophical work shows that characterizing determinations can be constructed which go against any classical logical law. The object the square such that it is not the case that it is square is characterized as being square and also being such that it is not the case that it is square. These two determinations, however, lead to a contradiction involving external negation. (See Routley 1980; Simons 1992: 185; Thrush 2001b.)