concurring.
The times being what they are, it is appropriate to add a word by way of emphasis to the Court’s opinion, which I join.
The case concerns the power of a State to exact from teachers in one of its colleges an oath that they are not, and for the five years immediately preceding the taking of the oath have not been, members of any organization listed by the Attorney General of the United States, prior to the passage of the statute, as “subversive” or “Communist-front.” Since the affiliation which must thus be forsworn may well have been for reasons or for purposes as innocent as membership in a club of *195one of the established political parties, to require such an oath, on pain of a teacher’s loss of his position in case of refusal to take the oath, penalizes a teacher for exercising a right of association peculiarly characteristic of our people. See Arthur M. Schlesinger, Sr., Biography of a Nation of Joiners, 50 Am. Hist. Rev. 1 (1944), reprinted in Schlesinger, Paths To The Present, 23. Such joining is an exercise of the rights of free speech and free inquiry. By limiting the power of the States to interfere with freedom of speech and freedom of inquiry and freedom of association, the Fourteenth Amendment protects all persons, no matter what their calling. But, in view of the nature of the teacher’s relation to the effective exercise of the rights which are safeguarded by the Bill of Rights and by the Fourteenth Amendment, inhibition of freedom of thought, and of action upon thought, in the case of teachers brings the safeguards of those amendments vividly into operation. Such unwarranted inhibition upon the free spirit of teachers affects not only those who, like the appellants, are immediately before the Court. It has an unmistakable tendency to chill that free play of the spirit which all teachers ought especially to cultivate and practice; it makes for caution and timidity in their associations by potential teachers.
The Constitution of the United States does not render the United States or the States impotent to guard their governments against destruction by enemies from within. It does not preclude measures of self-protection against anticipated overt acts of violence. Solid threats to our kind of government — manifestations of purposes that reject argument and the free ballot as the means for bringing about changes and promoting progress — may be met by preventive measures before such threats reach fruition. However, in considering the constitutionality of legislation like the statute before us it is necessary to *196keep steadfastly in mind what it is that is to be secured. Only thus will it be evident why the Court has found that the Oklahoma law violates those fundamental principles of liberty “which lie at the base of all our civil and political institutions” and as such are imbedded in the due process of law which no State may offend. Hebert v. Louisiana, 272 U. S. 312, 316.
That our democracy ultimately rests on public opinion is a platitude of speech but not a commonplace in action. Public opinion is the ultimate reliance of our society only if it be disciplined and responsible. It can be disciplined and responsible only if habits of open-mindedness and of critical inquiry are acquired in the formative years of our citizens. The process of education has naturally enough been the basis of hope for the perdurance of our democracy on the part of all our great leaders, from Thomas Jefferson onwards.
To regard teachers — in our entire educational system, from the primary grades to the university — as the priests of our democracy is therefore not to indulge in hyperbole. It is the special task of teachers to foster those habits of open-mindedness and critical inquiry which alone make for responsible citizens, who, in turn, make possible an enlightened and effective public opinion. Teachers must fulfill their function by precept and practice, by the very atmosphere which they generate; they must be exemplars of open-mindedness and free inquiry. They cannot carry out their noble task if the conditions for the practice of a responsible and critical mind are denied to them. They must have the freedom of responsible inquiry, by thought and action, into the meaning of social and economic ideas, into the checkered history of social and economic dogma. They must be free to sift evanescent doctrine, qualified by time and circumstance, from that restless, enduring process of extending the bounds of understanding and wisdom, to assure which the freedoms *197of thought, of speech, of inquiry, of worship are guaranteed by the Constitution of the United States against infraction by National or State government.
The functions of educational institutions in our national life and the conditions under which alone they can adequately perform them are at the basis of these limitations upon State and National power. These functions and the essential conditions for their effective discharge have been well described by a leading educator:
“Now, a university is a pláce that is established and will function for the benefit of society, provided it is a center of independent thought. It is a center of independent thought and criticism that is created in the interest of the progress of society, and the one reason that we know that every totalitarian government must fail is that no totalitarian government is prepared to face the consequences of creating free universities.
“It is important for this purpose to attract into the institution men of the greatest capacity, and to encourage them to exercise their independent judgment.
“Education is a kind of continuing dialogue, and a dialogue assumes, in the nature of the case, different points of view.
“The civilization which I work and which I am sure, every American is working toward, could be called a civilization of the dialogue, where instead of shooting one another when you differ, you reason things out together.
“In this dialogue, then, you cannot assume that you are going to have everybody thinking the same way or feeling the same way. It would be unpro-gressive if that happened. The hope of eventual development would be gone. More than that, of course, it would be very boring.
“A university, then, is a kind of continuing Socratic conversation on the highest level for the very best people you can think of, you can bring together, about the most important questions, and the thing that you must do to the uttermost possible limits is *198to guarantee those men the freedom to think and to express themselves.
“Now, the limits on this freedom, the limits on this freedom, cannot be merely prejudice, because although our prejudices might be perfectly satisfactory, the prejudices of our successors or of those who are in a position to bring pressure to bear on the institution, might be subversive in the real sense, subverting the American doctrine of free thought and free speech.” Testimony of Robert M. Hutch-ins, Associate Director of the Ford Foundation, November 25, 1952, in Hearings before the House Select Committee to Investigate Tax-Exempt Foundations and Comparable Organizations, pursuant to H. Res. 561, 82d Cong., 2d Sess.