This chapter that deals with post-classical realism must be seen against the background of its deliberate move away from human nature toward billiard balls. The transformation from Morgenthauian/Niebuhrian-style political realism to post-classical realism was the outcome of an increasing dissatisfaction with the former's reliance on what post-classicals considered unscientific and crude human-nature speculations. Post-classicals set out to supersede the older (genuine) political realism with a newer, more scientific realism.