[en] We discuss a 1 + 1 dimensional field theory which is not integrable classically but becomes so when a coupling β² (which can be scaled out of the action and plays the role of temperature in the euclidean path integral for the quantum theory) equals 4π. Also at this critical coupling the symmetry group changes from the (discrete) Weyl group of O(2N) to O(2N) itself. The group acts not on the N real scalar fields in the lagrangian but on the solitions which carry the O(2N) charges topologically. The analogy to a similar phenomenon, conjectured to exist on 3 + 1 dimensional gauge theories with monopoles, is pursued. The relevance to preon physics and unification is discussed. (orig.)