Poland in a period of Russian domination is not the best place to sound off on shortcomings of the Soviet system or to complain of restraints on freedom, so it came as no great surprise to Leszek Kolakowski that he was fired in 1968 from his professorship at the University of Warsaw. Since then he has taught at various colleges, currently dividing his time between All Souls, Oxford, and the University of Chicago.

Tonight he delivers the Jefferson Lecture (the most prestigious symbol of federal interest in the humanities, carrying a stipend of $10,000) at the National Building Museum in the Pension Building to an invitation-only audience. His topic will be "The Idolatry of Politics," and by idolatry he means the ascription of semidivine sanction to whatever has been decided on as state policy.

Kolakowski is a celebrated authority on philosophy and the history of ideas and has written some 30 books, notably his three-volume work on currents in Marxism, but also works on the history of modern philosophy, religious ideas, political philosophy and the philosophy of culture.

He is a thin man, who uses a walking stick of clear plastic. In deference to scientific superstition (as he puts it) he smokes cigarettes with filters, but a good many of them. He rejoices to meet fellow sinners. His eyes are settled blue, nothing tentative about them, though he often looks down, raising his head to give a clear, direct look at a visitor when he speaks. His hair is brown, much touched with gray, and one might guess he is 10 years older than his 59 years.

He has a reputation for irony, and he observed at a press conference yesterday (when asked his views on terrorism by someone who thought he might have something amazing to say on the subject) that he is always a bit surprised at those who call for dealing with the "root causes" of terrorism in, say, the Middle East.

The truth is, he said, that the Arab world would like to see the State of Israel "exterminated," and that alone, he said, would be a "perfect" solution to terrorism. But then, he went on, you would have to go farther back and "abolish" what happened at Auschwitz and the other death camps. The root causes, in other words, root back in history, which cannot now be changed. It is absurd, he believes, to speak of addressing root causes when they lie in a past beyond redress.

He is a believer in calling things by their right names, he said, and is fond of pointing out the contradictions of bombastic rhetoric, as when people call for peace and justice when one or the other can be chosen but not both.

He is famous (infamous in some places) for his belief in freedom and his championing of democracy; still, the dangers inherent in both are apparent to him.

If freedom is absolute, he points out, then the strong are free to run roughshod over the weak, and beyond a certain point this is not what the lovers of freedom have in mind. As for democracy, he does not forget the possible tyranny of the majority -- Hitler was supported by a majority, after all, and so was Mao, both of whom established totalitarian states in which freedom was obliterated.

We are great believers (to use one of his examples) in human rights and deplore their curtailment in, say, South Africa. In such a case we sound the moral trumpets briskly. But in other cases, we do not sound off at all, either because of "cowardice" or for some political reason. We are selective, in other words, in our application of moral fervor.

A thing that concerns him greatly, he said, is a kind of neutrality that he believes is increasing. As if one were to say we have our values, the totalitarians have theirs -- and as if there were nothing much to choose between them. The period of the Enlightenment, he said, from which so many modern liberal democratic values descend, advanced tolerance and a pluralistic national life to a point at which one value system is thought as valid as another.

But in his view, the civilization of the West -- certainly its belief that human life is valuable even apart from a particular human's usefulness to the state -- should be defended at any cost against a system in which a human is judged and treated only in accordance with his usefulness (or troublesomeness) to the state.

He detects, he says, an increasing loss of those old and former moorings to which moral ideas were attached and from which they sailed forth. Christianity, he mentions, believed strongly in absolute values, derived from God -- even though people frequently twisted them to their own purposes or even defied them.

There were other values once more widely held than now, he said -- a sense of oneself as an inheritor of the past, free to make changes but still aware of, and affected by, what has gone before in human history. And people used to believe, more generally than now, he suspects, that a human personality is more than the blank on which the environment has acted. Now, instead, many more people think a human is conditioned almost totally by the society around him.

If there is no such thing as right and wrong built into the universe itself, then men are less likely to assume responsibility for all that happens in the world.

He has no grand answers, he said -- intellectuals are not in a position to dream up a new faith as pervasive as some of the old lost ones -- but can at least point out the dangers. And he can at least prevent our assuming (as many do, he says) that the East-West tensions are simply power struggles between states, when in fact they are conflicts between civilization as it has been known in Europe in the past (for all its shortcomings and horrors) and a different civilization in which none of those old values has any force at all.

Truth in such a society is whatever serves the immediate interest of the state, and a lie is simply (as he has written elsewhere) whatever does not. This is different from the western notion that there is such a thing as truth, even if we deliberately lie for some purpose of our own.

If you ask him what people should do -- assuming the absolutes of divine law have been lost, and also assuming that a totalitarian system is undesirable -- he will go so far as to say it is not intellectually dishonest to believe in values that cannot be guaranteed, or even recognized, in the rigors of scientific or philosophic thought. You cannot "prove" slavery is wrong by rigorous thought, but you might not be wrong to think it wrong all the same.

If you ask him what the difference is between the "selectivity" practiced in moral fervor now and the selectivity practiced, say, under Christianity in the Middle Ages (or any other time), he will say there was a core in religion that men truly believed in, however poorly they behaved.

And if you ask him if it's possible that ordinary people have not drifted so far from the supposedly lost values of the past, he will simply say quietly:

"I hope so."