Ex Concessis

Lat. ex concesso, pl. ex concessis; concessus, “concession, consent”.
Lat. ex concessu gentium: gentium, from gens “race, nation, people” translated as “argument from the consensus of nations”.

The Latin label ex concessis refers to two kinds of argumentation.

— Argumentation based upon the (alleged) universal consensus (ex concessu gentium), that is to say, from general agreement, S. Consensus; Authority.

— Argumentation based upon a local consensus, limited to the beliefs of the audience. The orator may or may not share these beliefs. With this meaning, the argument ex concessis is also called ex datis.