Opinion (n.) is no different from knowledge, held firmly enough — Heraclitus held his own dogmas that way.
Opinion (n.) is the raw material of argument, and since men's opinions often contradict each other, every syllogism has a counter-syllogism.
Opinion (n.) is to knowledge as sickness is to health — so those with only opinions should be the most anxious about truth.
Opinion (n.) is the state that is sometimes knowledge and sometimes ignorance — which is why perishable individuals can only be opined, never defined.
Opinion (n.) can rot into falsehood, held unchanged: think truly that a man sits, keep thinking it after he rises, and you are wrong without having moved.
Opinion (n.) held by many over a long time, or by a few distinguished people, is unlikely to miss the mark completely; each has got something, perhaps much, right.