“Opinion” from the Latin *opinari*, meaning “to think”… While a fact describes reality – existents and/or their relationships – an opinion describes a class of thoughts. Specifically, it refers to the thoughts of a particular person that constitute a conclusion of his thinking at a particular time that certain facts are valid – that certain descriptions are accurate.
I would not distinguish between a fact and an opinion by reference to the rationality, validity, accuracy, or provability of their content, because both can be any of these or their opposite depending on the context. The temptation to allot an inherent value such as “unprovable” to “opinion” is a symptom of lingering infection by a contemporary intellectual plague: the misuse of the word “opinion” to evade and destroy reason by twisting it into a synonym for “invalid”.
“Yeah? Well that’s just your opinion” is the ultimate weapon of the mindless when cornered by a rational argument. The qualifier “just” and the tone of voice in which this statement is uttered is a clear attempt to negate the efficacy of any and all reason communicated in the form of an opinion. And how else does the communication of reason occur?
This is the down end of the Kantian trickle. The misusers can concede that an opinion refers to thoughts about the validity of facts, and can even concede that facts can be valid or invalid. But they sustain at all costs the belief that as long as the facts are “*just* your opinion”, they lack the efficacy of facts “validated” by a consensus (of experts or masses). They cling to that, because that is their excuse to escape the work and responsibility of rational thought. Without any ability to use or cope with the concept of objective validity, they have defaulted to agreement with a consensus as their only standard for or approximation of validity.
The tactic is ubiquitous, because it is so effective. Most of the population takes the same belief for granted and capitulates to the statement without resisting. The few rational enough to grasp the underlying deceit expect that the users are unlikely to be willing or able to understand the error committed even if it were pointed out to them and don’t try.
If you reply that you are able to prove the facts your opinion contains, the misusers will repeat the claim that your proof is likewise just your opinion. If you reply, “my opinion as opposed to what?” They will respond with, “what do you mean by that?” and initiate obfuscation. If you fail three times to ignite a spark of rationality, change the subject or walk away.
Nevertheless, it is worthwhile to continually hone your best reply to this tactic. Often its usage is powered more by bad habit than irrationality in a mind that can still be rescued. Also, when arguing in groups, there is, more often than not, on the periphery, a silent observer absorbing intently and intelligently every word you speak.
MichaelM