The political thinker Niccolo Machiavelli makes a sweeping defense of republican liberty and public speech in his Discourses on Livy from around 1517. The book is published posthumously in 1531.
”…a people is more prudent, more stable, and of better judgment than a prince… as to the justice of their opinions on public affairs, [we] seldom find that after hearing two speakers of equal ability urging them in opposite directions, they do not adopt the sounder view, or are unable to decide on the truth of what they hear.
The prejudice which is entertained against the people arises from this, that any man may speak ill of them openly and fearlessly, even when the government is in their hands; whereas princes are always spoken of with a thousand reserves and a constant eye to consequences.”
– Machiavelli, Discourses on Livy, ch. 58
Read the full book here.