The idea here is that while everyone (animals included) is capable of reaction, only a rarefied minority is capable of genuine action. Action, from this perspective, means leadership, which in turn implies a far larger quantity of followership. Combating this mentality requires us to think of action democratically, as something made possible by the fact of human plurality. Thus all action is in fact interaction.
Compare the Romantic artist vs. the writer-as-cabinetmaker, composer-as-mechanic