Library shelves groan, as do undergraduates, beneath the weight of classics of political philosophy. Not one of those is about international relations. The philosophically interesting dilemmas of social life concern people living in community, under a common sovereignty, dealing with the concepts of rights, justice, consent, representation, obligation and so on.

Writings about international relations tend either to be called forth by particular events, and to be as perishable as the contexts, or to be highly general prudential maxims. Gary Hart was, therefore, undertaking something difficult recently when he delivered three lectures on "a foreign policy framework for the 21st century."

Imagine how a "framework for the 20th century," written in 1886, would have read 50 years later: "As regards relations between the Czarist and Hapsburg regimes . . ." Still, Hart has made a brave effort to think systematically about foreign policies, which are necessarily episodic.

America, says Hart, has had three foreign policy phases. From the founding until the turn of this century, there was isolationism, a product of principle, as well as geography. Next, a "making the world safe for democracy" phase lasted until the late 1940s, when it was replaced by containment. Now, Hart says, a fourth framework -- "enlightened engagement" -- is needed.

"The great diffusion of military, political and economic power," and the rise of Third World nationalism, mean that the goal of containment "can depend increasingly on local, rather than American, resistance to Soviet expansionism." That is an arguable proposition. It may be true, or at least (as the saying goes) close enough for government work. But Hart's words set off intellectual smoke detectors in the minds of those who think the Democratic Party is guilty, until proved innocent, of McGovernism.

From the birth of totalitarianism in 1917, when Woodrow Wilson became its active enemy, through FDR's leadership against Europe's dictators, through Truman's response to the Berlin Blockade, the threat to Greece and the Korean War, through Kennedy's and Johnson's commitment of U.S. power against communism in Indochina -- through all that, the Democratic Party was the world's foremost foe of totalitarianism. Its record of constancy was superior to that of the GOP. Then came the 1972 capture of the Democratic Party by people who considered the party's post-World War II record dishonorable and discredited by the party's role as architect of the Vietnam intervention.

Hart, who became prominent directing McGovern's 1972 campaign, participated, in 1984, in one of the most telling episodes of recent politics. In the New York primary campaign, he and Walter Mondale engaged in a downward-bidding competition to see who could pledge to withdraw U.S. forces from the most places. Hart won by a whisker when Mondale said he would allow a couple dozen U.S advisers in Honduras.

It is, therefore, encouraging to hear Hart describe Moscow's behavior as a "drive for hegemony" and to say that the drive "is not likely to dissipate in our lifetime." But the smoke detectors go off again when, being rhetorically too clever by half (Jeane Kirkpatrick's "blame America first" charge still stings Democrats), Hart criticizes what he calls a "credit Russia first" mentality, which sees the hand of a Soviet puppeteer guiding every movement or government hostile to us.

"This mentality," he says, "often creates self-fulfilling prophecies. Heavy American pressure can drive such forces into the Soviet harbor as the only available port in the storm. Nicaragua is partly a case in point."

A "new idea"? Hardly. It comes close to blaming America for the communist behavior of Nicaragua's communists, just as in the 1960s voices on the left blamed America for "driving Castro into Moscow's embrace."

Hart's analysis is especially labored when he brands, by implication, President Reagan as an isolationist. Hart says, among other things, that those who are skeptical about arms control, who favor the Strategic Defense Initiative and support unilateral military action, isolate America from its allies and frighten Americans into associating internationalism with loss of life.

It is at least as arguable that isolationism today comes cloaked in the language of multilateralism. A reluctance to act other than in concert with allies achieves the traditional goal of isolationism: it immobilizes America, by making America hostage to the most hesitant member of the alliance. Isolationism is a policy of passivity, not solitariness.

However that may be, credit Hart for the following:

In 1984, he was hurt by the suspicion that he was a plastic man, skin deep all the way through, and so preoccupied with the cosmetics of politics that he would change his name, even his signature -- the latter several times. His theme of "new ideas" was more theme than achievement. But Hart knows something: American elections are about ideas. He is playing the game as it ought to be played.