The paper first takes note of the difficulties met by Joan Robinson and her partisans and critics when attempting to pull together the post-Keynesian short-period approach and the classical long-period approach. In attempting to reach a post-classical synthesis, it is proposed to start from a Kaleckian model of growth and distribution, the price system of which would rely on the full cost approach, more precisely the target return principle, computed on the basis of a normal rate of capacity utilization. The second part of the paper describes such a model with excess capacities, while the third part deals with the analysis of the traverse from one steady-state to another within a two- sector framework. Dynamic stability issues and reproportionning are also dealt with. In conclusion it is noted that while some mechanisms may support the claims of those who argue that long-period analysis must be conducted on the basis of fully adjusted positions — linked to normal rates of utilization — this does not imply that the results and causations of the Keynesian/Kaleckian approach, along with its principle of effective demand, must be discarded in long run analysis. This conclusion arises as a consequence of the phenomenon of hysteresis, which transforms the normal rate of capacity utilization into a variable which itself is endogenous.