Full Idea
The very existence of reason depends on freedom, which has no dictatorial authority, but whose claim is never anything more than the agreement of free citizens, each of whom must be able to express reservations, indeed even veto, without holding back.
Gist of Idea
The existence of reason depends on the freedom of citizens to agree, doubt and veto ideas
Source
Immanuel Kant (Critique of Pure Reason [1781], B766/A738)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.643
A Reaction
I think the biggest conflict within modern societies (as opposed to currently existing medieval ones) is between the freedom that is required for a rational society, and the restraint which is required for a virtuous society. What has highest value?