In the following excerpt from "The Indispensable Opposition," what argument is Lippmann making in terms of man's freedom and toleration of opinion?
"Were they passed hard enough, most men would probably confess that political freedom – that is to say, the right to speak freely and to act in opposition – is a noble ideal rather than a practical necessity. As the case for freedom is generally put to-day, the argument lends itself to this feeling. It is made to appear that, whereas each man claims his freedom as a matter of right, the freedom he accords to other men is a matter of toleration. Thus, the defense of freedom of opinion tends to rest not on its substantial, beneficial, and indispensable consequences, but on a somewhat eccentric, a rather vaguely benevolent, attachment to an abstraction."
Walter Lippmann was a journalist trying to establish an argument for the need for the public intellectual. In certain ways, this essay seems to lean heavily on John Stuart Mill's seminal work, "On Liberty" which argues that since truth is discovered in the process of debate, conflicting voices in the public sphere are the guarantor not only of democracy, but of progress in all endeavours.
In the opening paragraph of the essay, which you have quoted, Lippmann is claiming that most people tolerate freedom of speech without valuing it, in the way we might put up with a neighbor's yapping dog. He is setting up an argument that rather than merely tolerate free speech, we should value opposing voices as necessary for the process of decision making in a democratic society.
In "The Indispensable Opposition," Walter Lippmann spoke of freedom and the importance of allowing and truly listening to dissenting voices. He begins by stating that most men view political freedom as a noble ideal but not as a practical reality. This is because, although they claim their own personal freedoms, they do not extend the same level of freedom to others, especially those on opposing sides. This situation ends up being driven by the need to tolerate other voices and may not involve listening or understanding. In that case the idea of freedom is lost because by just tolerating different opinions people miss the opportunity to improve on their understanding.
And so, if we truly wish to understand why freedom is necessary in a civilized society, we must begin by realizing that, because freedom of discussion improves our own opinions, the liberties of other men are our own vital necessity.
Walter Lippmann is supporting the need for true liberty and the need for the opposition in every civilized territory. He opines that leaders cannot hold one-way conversations with their people and expect successful leadership or societies.