Using data mostly from American politics and comparative studies, Professor Penn argues that general systems theory "is often regarded as appropriate as the most general framework for political science. " But he feels also that we need to be far more careful and sophisticated in our use of it. Reading it in conjunction with Weltman's article which follows, one is struck with the degree to which Weltman anticipates Penn's arguments. Is he right? Doubtless Penn or others will return to the attack; nor in any case can one expect a single article to kill an entire move-