Reason holds little social power or influence on its own. It becomes powerful amidst prosperity where well rested people with full bellies can use evidence and logic to settle disputes or invent the next best thing.
When civilization begins to crumble so too does the power of a well-reasoned argument.
Civilization is the only thing that grants the pen more power than the sword. When the dark age comes (and it always comes) the power increasingly lies with those skilled with a blade.