opinion

Cicero used opinio in the first century BC to mark the difference between knowing and guessing. Scientia was reserved for what could be demonstrated; opinio covered everything else: the probable, the rumored, the merely believed. He laid this distinction out in his Academica around 45 BC, borrowing vocabulary from Greek epistemology but making it thoroughly Roman. The word descended from opinari, to suppose or hold a view, which may share a root with optare, to choose.

Medieval philosophers carried opinio into their universities with the same tension Cicero had felt. In scholastic disputation, a student who offered an opinio was not asserting truth but entering a negotiation. Thomas Aquinas, writing in Paris in the 1260s, used the word hundreds of times in the Summa Theologiae to signal positions that were argued, not settled. Opinion was a posture, not a verdict.

Old French opinion appeared in texts by the twelfth century, and Middle English borrowed it as opinioun by the 1300s. Chaucer used the form in Troilus and Criseyde around 1385, already with the flavor of personal conviction rather than collective certainty. The spelling settled toward opinion by the sixteenth century, and Shakespeare used it with a slight edge, often meaning reputation or public esteem as much as private belief.

By the seventeenth century, opinion had split into two streams. One was the intimate private judgment, what a person holds for themselves. The other was the collective voice of a public, the kind of force Edmund Burke would study in the following century as the governing pressure in free societies. Newspapers began reporting public opinion as if measuring a natural fact. The word had traveled from Cicero's private episteme to a political force requiring its own polling industry.