It is not the function of the government to keep the citizen from falling into error; it is the function of the citizen to keep the government from falling into error.
Freedom to differ is not limited to things that do not matter mush. That would be a mere shadow of freedom. The test of its substance is the right to differ as to things that touch the heart of the existing order.
If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of opinion, or force citizens to confess by word or act.
Those who begin coercive elimination of dissent soon find themselves exterminating dissenters. Compulsory unification of opinion achieves only the unanimity of the graveyard.
To believe that patriotism will not flourish if patriotic ceremonies are voluntary... is to make an unflattering estimate of the appeal of our institutions to free minds.