THE SUPREME COURT'S ruling the other day that corporations have a constitutional right to express their views on political issues is a thunderbolt in law and politics. It breaks open questions long thought to have been closed. It raises the possibility that not only corporations but also comparable entities - labor unions, associations, partnerships - will become even more deeply involved than they are now in elective politics. And it helps to diminsh the corporation's peculiar status as "an artificial being, invisible, intangible," to use the memorable phrase of Chief Justice John Marshall. Legally a corporation is now a "person" with at least some fundamental rights and a voice the government cannot still.

Among the central questions the decision raises are these: Since government cannot limit the amount of money an individual spends directly on a political campaign (although it can limit contributions to candidates), can it limit the amount a corporation spends? Is there any difference between corporations and labor unions in terms of expressing political views and spending on campaigns? Can lobbying activities of corporations be regulated differently from the activities of individuals? Which of the other rights and protections given to individuals by the Bill of Rights now apply to corporations with equal force? How many other attributes of real persons will the law or the courts eventually hand over to these artificial "persons?"

We don't know anybody who claims to know the answers to those questions with any certainty - which is precisely why we are troubled by the direction in which the court seems to be heading. A corporation, after all, is quite different from a human being. Most are created for only one purpose - making money - and are endowed with at least one quality human beings lack: potential immortality. Their stake in the politics of a nation is considerable. But they lack the mechanism for self-expression that has usually been thought of as the core of the First Amendment. Corporations are not minds that formulate ideas or even voices that freely express them. Rather, in a political debate corporations are megaphones for the views of those who own or control them. Yet corporations do not represent the majority view of all those who are shareholders in them. Corporations, in short, are money talking.

How, then, did the court come to this view that a corporation has a First Amendment right to participate in political discussion? It did so by looking at freedom of speech from the listener's, not the speaker's, point of view. Justice Lewis F. Powell, who wrote the majority opinion, believes the real meaning of free speech lies at least as much in "affording the public access to 'discussion, debate and the dissemination of information and ideas" as in fostering individual self-expression. What counts is the content of speech, not its source.

That view, a fairly new one in the court, grows out of decisions that extended First Amendment protections to publishing and broadcasting corporations. Since a corporation such as that which publishes this newspaper enjoys the right to freedom of the press, the argument goes, other corporations must enjoy the right to freedom of speech. In the last two years, that analysis has been used to establish at least some First Amendment protection for advertising (commercial speech).

That rationale for what the court has done is not lacking in logic and appeal. But we find more persuasive the dissenting, traditional views of Justices Byron R. White and William H. Rehnquist. Justice White pointed out that the public would be unlikely to lose either ideas or information if corporations could not participate in political debate; the information would be perfectly free to communicate them as individuals. Justice Rehnquist noted that the court has previously extended the protections of liberty contained in the Bill of Rights only to publishing corporations and to associations created for political purposes. A basis can also be found in prior cases for a quite different decision, one that would have permitted government to restrict the speaking right of corporations and other such entities to those matters that directly affect the business in which they are engaged.

It will take years to comprehend the full dimensions of the change the court is making in the First Amendment. Presumably, one immediate result is that the view of IBM or AT & T or the AFL-CIO concerning, say, the Panama Canal treaties or who should be president can now be spread as widely as the views of a newspaper or individual, if those who control the former organizations want to make the effort. If that will mean more robust and enough to us. But if it will mean that the voices of those with the most money will have an unfair advantage over other voices in political debate, we do not see how that would usefully serve the purposes of free speech.