OK good examples from those that bothered answering the topic.
(I see iceman has the curfew mentality firmly embedded in his occupied brain.)
Dino I agree many opinions could be backed up, but we can make value judgements on how they are arrived at, and then decide if they are equally valid to more sustainable views....
Surely that's what Humans are good at: weighing up the evidence and making decisions. Meaning not all opinions are equally valid.
My example:
The Pope has no scientific knowledge yet he firmly refutes the evidence from Evolution, that Creation by a God, was not necessary to put life on Earth.
Dawkins is the leading authority on the vast data and research we have which profoundly prove life can be "created" in a test tube, even by us mere mortals. This eliminates the central doctrine for a need of a "Creator-God".
Surely the Pope's opinion is then not equally valid, arising without justification or foundation, to that of Dawkins', in establishing whether Creation or Evolution, should be taught in Biology classes at schools.