Abstract
The classical theory of scattering for a two‐body problem by Prigogine and Henin, Résibois, and Miles and Dahler is extended to include a three‐body system in which exchange reactions are allowed as well as excitations in the internal states. The results obtained are parallel to those in the quantum mechanical three‐body theory of Faddeev and given in such a way that an introduction of approximation methods is possible without difficulty.