Opposability

Among the Primates themselves there is a whole group of living species, the South American marmosets, that, in the fore feet at least, show no evidence of opposability, although they are strictly arboreal in habits.

This consequence remains hidden as long as custom is thought in terms of "opposabilities" in which the States' conduct is interpreted so as to render the same norm.

Although no provision of the Civil Code lays down the principle of invocability, it is nonetheless unanimously admitted and is found in substantive law in two forms: the opposability of the contract to third parties, and the opposability of the contract by third parties.