  We draw the connection between the model theoretic notions of internality and
the binding group on one hand, and the Tannakian formalism on the other. More
precisely, we deduce the fundamental results of the Tannakian formalism by
associating to a Tannakian category a first order theory, and applying the
results on internality there. We also formulate the notion of a differential
tensor category, and a version of the Tannakian formalism for differential
linear groups, and show how the same techniques can be used to deduce the
analogous results in that context.
