Even in a relatively quiet and sober decade, such as the seventies, one can hardly subscribe to Daniel Belt's evidently premature judgment about "the end of ideology". Ideologies may no longer sound so biased, militant and aggressive as in the days of the Cold War, but they still dominate the whole world of politics and culture. Humankind is still divided into ideologically exclusive camps. Many economic, political and ecological problems cannot be solved in optimal ways for ideological reasons. Rather than withering away, ideologies tend to multiply and grow in complexity. In addition to traditional class struggles, new conflicts break out and new social movements have been generated: those of rebellious youth, oppressed races, women, national and religious communities. Each of them tends to create a new ideology: the New Left, feminism, black racism as opposed to white racism, various forms of nationalism, and of (Zionist and Islamic) religious ideology. Philosophy was never able to preserve its purity from various ideological intrusions. On the contrary, it was philosophers who pro vided theoretical foundations for all three of the most important political ideologies of our times: liberalism, Marxism and fascism. And it could be shown that even the most strictly anti-metaphysical, anti-speculative, consequently anti-ideological contemporary trend that of analytical philosophy tacitly assumes some of the basic premises of liberalism. Now when analytical philosophy is opened up for historical study and value judgments, it will even less be able to keep its distance from ideological considerations. And yet philosophy, because of its commitment to unbiased thinking and universal values, is better equipped than any other form of inquiry to provide a critique of ideology and ideological reasoning. The first question we have to discuss is then the following: What is ideology? How can it be distinguished from philosophy, science, and rhetorics? What are the basic logical characteristics of the language of ideology?