“ OPINION (Lat. opinio, from opinari, to think) , a term used loosely in ordinary speech for an idea or an explanation of facts which is regarded as being based on evidence which is good but not conclusive. In logic it is used as a translation of Gr. δόξα, which plays a prominent part in Greek philosophy as the opposite of knowledge (ἐπιστήμη or ἀλήθεια) . The distinction is drawn by Parmenides, who contrasts the sphere of truth or knowledge with that of opinion, which deals with mere appearance, error, not-being. ”