Maximilien Robespierre

If virtue be the spring of a popular government in times of peace, the spring of that government during a revolution is virtue combined with terror: virtue, without which terror is destructive; terror, without which virtue is impotent. Terror is only justice prompt, severe and inflexible; it is then an emanation of virtue; it is less a distinct principle than a natural consequence of the general principle of democracy, applied to the most pressing wants of the country. ... The government in a revolution is the despotism of liberty against tyranny.