The idea of the third refers to a position in which we transcend opposites or hold them in mind without cancelling out one side. Regarding differences with others or enemies, it means a viewpoint from which it is possible to see the validity of more than one side, to see the injuries inflicted and suffering endured by both. The third position, like the third point on a triangle, allows us to relate to both points at the end of the straight line and to create a space. To occupy that space in a psychological sense would mean, as Benjamin suggests, holding to a basic principle of recognition, for instance, that all human beings deserve recognition of their common humanity. We might think of the third as a space of recognition and dialogue, beyond simple oppositions.
(Tertium quid refers to an unidentified third element that is in combination with two known ones. The phrase is associated with alchemy.It is Latin for "third thing")