Against this chance of internal assailants Kleisthenês had to protect the democratical constitution,—first, by throwing impediments in their way and rendering it difficult for them to procure the requisite support; next, by eliminating them before any violent projects were ripe for execution. To do either the one or the other, it was necessary to provide such a constitution as would not only conciliate the good-will, but kindle the passionate attachment, of the mass of citizens, insomuch that not even any considerable minority should be deliberately inclined to alter it by force. It was necessary to create in the multitude, and through them to force upon the leading ambitious men, that rare and difficult sentiment which we may term a constitutional morality; a paramount reverence for the forms of the constitution, enforcing obedience to the authorities acting under and within those forms, yet combined with the habit of open speech, of action subject only to definite legal control, and unrestrained censure of those very authorities as to all their public acts,—combined too with a perfect confidence in the bosom of every citizen, amidst the bitterness of party contest, that the forms of the constitution will be not less sacred in the eyes of his opponents than in his own. This coexistence of freedom and self-imposed restraint,—of obedience to authority with unmeasured censure of the persons exercising it,—may be found in the aristocracy of England (since about 1688) as well as in the democracy of the American United States: and because we are familiar with it, we are apt to suppose it a natural sentiment; though there seem to be few sentiments more difficult to establish and diffuse among a community, judging by the experience of history. We may see how imperfectly it exists at this day in the Swiss cantons; and the many violences of the first French revolution illustrate, among various other lessons, the fatal effects arising from its absence, even among a people high in the scale of intelligence. Yet the diffusion of such constitutional morality, not merely among the majority of any community, but throughout the whole, is the indispensable condition of a government at once free and peaceable; since even any powerful and obstinate minority may render the working of free institutions impracticable, without being strong enough to conquer ascendency for themselves. Nothing less than unanimity, or so overwhelming a majority as to be tantamount to unanimity, on the cardinal point of respecting constitutional forms, even by those who do not wholly approve of them, can render the excitement of political passion bloodless, and yet expose all the authorities in the state to the full license of pacific criticism.