Getting to know Reagan

He rides tall in the saddle, but he's no gunslinging cowboy. This is the Ronald Reagan whom Europe is finally getting to know firsthand. As the US President moves on to Bonn he can be sure his trip thus far has not let down the tens of thousands of West Germans who rallied for America there last weekend.

The Germans were trying to steal a march on the other thousands expected to rally against his arms policies today. But Mr. Reagan -- who has proved he can be disarming in more ways than one -- is his own best advocate. There he was, taking a royal horseback ride one moment and talking peace to members of Britain's Parliament the next. Cracking a joke or two, he was the California Yankee at Queen Elizabeth's Court, as Mark Twain didn't quite say.

However, Mark Twain did say: ''Loyalty to petrified opinion never yet broke a chain or freed a human soul.'' And Mr. Reagan's journey has been challenging some fairly petrified opinions about how to spread the margins of freedom.

Not that his alternatives are necessarily the best to come down the pike. But they confront his audiences with choices that can help jar thinking - into acceptance of Reagan ideas, defense of traditional ones, or promotion of other options.

For example, Mr. Reagan announced in his London address a new campaign for democracy throughout the world by supporting such institutions as a free press, free political parties, and free trade unions. An immediate response might be concern about American interference in other countries, as in Chile in the past.

But Mr. Reagan's intention evidently is not to unleash the CIA for more covert financing in other countries. Rather he is contemplating both private and governmental support. (America's AFL-CIO has already been supporting the Solidarity union in Poland.) And the first step would be a study involving both the Republican and Democratic parties in the United States.They must do their job with care to ensure that the US does not infringe on freedoms in the attempt to expand them.

President Reagan showed that he does not intend to be the prisoner of his own opinions either. After appearing for so long as the entrenched hard-liner against the Soviet Union, he now extends the hand of peace. He still wants to see communism consigned to ''the ash heap of history.'' But he wants peaceful competition between it and the forces of freedom. He invites Mr. Brezhnev to speak to the American people if Mr. Reagan can speak to the Soviet people. Why not? President Nixon spoke in the Soviet Union; Brezhnev (and Khrushchev) spoke in the US. Mr. Reagan suggests that Soviet journalists appear on US television and American journalists appear on Soviet TV. Again, why not? Unless Moscow only dares the quid but not the quo.

At any rate, these are not the words of a lonely cowboy, finger on trigger against a hostile world. They sound more like a man looking around him and seeing that just maybe people can be brought together in peace and freedom, if petrified opinions are subjected to debate.