  In this note we prove the geometrical origin of pairings of abelian schemes.
According to Deligne's philosophy of motives, this means that these pairings
are motivic. We make also explicit the link between pairings and linear
morphisms. We give a geometrical explanation of the main properties of the Weil
pairings and of the Riemann forms of line bundles. We generalize our remarks to
pairings of 1-motives.
