It is quite generally thought to be commendable, but only marginally worth-while, for a political theorist to devote any great attention to economic assumptions, much less to economic theory. The general separatist trend of political science is quite understandable. As political science becomes a more confident, more developed, and more extensive discipline, the natural tendency is for it to seek a greater measure of independence. Along with the trend to separatism in political science has been a marked trend towards empirical, value-free analysis. The concern with values, which was central in the great theoretical writing on politics in the past, has been pushed out to the fringes of the subject as empirical work has proliferated.

I am going to suggest that both these trends are now rather dangerous, that they are a result of overconfidence in the strength of liberal-democracy. I shall argue that political science is now more than ever in need of rethinking its normative theory, and of doing so in full consciousness of the bearing of economic systems and economic assumptions on that theory. Political values have become more, not less, in need of central attention in political science, and economic assumptions more, not less, important in political theory.

The first of these contentions should not need much argument. In these days of uncertain co-existence, everyone in the liberal-democratic world who thinks about politics can see that political value systems, political ideologies, or call them what you will, are of great practical importance. There are, we may say, vis-`-vis co-existence two classes of people—believers in hostile co-existence and believers in peaceful co-existence. Believers in hostile co-existence see a battle of irreconcilable ideologies, and see a need to sharpen ours. Believers in peaceful co-existence see a present competition of hopefully reconcilable ideologies, ideologies which they hope are both changing in ways that could lead to their supersession by something containing the basic values of both. No one in his senses is outside one of these two groups. No one who has a rudimentary knowledge of the consequences of military technology believes that co-existence can be ended by all-out military action. It can only be ended by such internal development of one or both existing systems as would transform their relationship into something not adequately described as co-existence.

We can take as given, then, the necessity for some kind of co-existence between two systems and two ideologies, until such time as the terms of existence are transformed. We can also take it as given that there has already been some change in the ideologies or the justifying theories of both liberal-democracy and communism since their classic formulations, though whether the changes have been sufficient to take account of new facts is open to question. It follows that there is need for continued enquiry by liberal-democrats into the rationale of the liberal-democratic society and state. We need to ask whether our theory is all that it might be, and, if not, on what lines we should proceed.

Although this conclusion seems to follow from a recognition of the facts of change, it is not a conclusion that has been generally drawn or widely acted upon by the theorists and publicists of politics in the liberal-democratic world. There has been some disposition among theorists not to let such practical matters as co-existence enter their consciousness at the level of their theoretical work. Others have admitted the facts but sought to conjure them away. It is not generally questioned that there have been some changes, in both practice and theory, in both the liberal-democratic and the communist worlds since the two systems first took shape. One reaction to this has been to claim that one or the other has changed out of all knowing, with the implication that the problems we have failed to solve are no longer real problems.