duality
noun [ U ] formal uk/dʒuːˈæl.ə.ti/ us/duːˈæl.ə.t̬i/
双重性，二元性
the state of combining two different things
His poems reveal the duality of his nature, the joy and hope, the fear and despair. 他的诗揭示了他的双重本性，既有欢乐且充满希望的一面，又有恐惧失望的一面。
Compare: dichotomy