At the heart of the First Amendment is the recognition of the fundamental importance of the free flow of ideas and opinions on matters of public interest and concern. The freedom to speak one's mind is not only an aspect of individual liberty – and thus a good unto itself – but also is essential to the common quest for truth and the vitality of society as a whole. We have therefore been particularly vigilant to ensure that individual expressions of ideas remain free from governmentally imposed sanctions. The First Amendment recognizes no such thing as a "false" idea.