Premise:  Poussin's bittersweet Arcadian Shepherds; Watteau's melancholy Gilles and graceful Embarkation for Cythera; Dela?­croix's Liberty Guiding the People; and Courbet's penetrating study of provincial bourgeois life, Funeral at Ornans.

Hypothesis: Da Vinci's bittersweet Arcadian Shepherds, George Bush's melancholy Gilles and graceful Embarkation for Cythera.
Relation: contradiction