a belief that can guide behavior; "the architect has a theory that more is less"; "they killed him on the theory that dead men tell no tales"
a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses"; "true in fact and theory"
the reason for a court's judgment (as opposed to the decision itself)
a personal belief or judgment that is not founded on proof or certainty; "my opinion differs from yours"; "what are your thoughts on Haiti?"
the legal document stating the reasons for a judicial decision; "opinions are usually written by a single judge"
a message expressing a belief about something; the expression of a belief that is held with confidence but not substantiated by positive knowledge or proof; "his opinions appeared frequently on the editorial page"