Well, if biology only makes sense in the light of evolution, then opinions make only sense in the light of jokes. The world of opinions are like worlds of cartoons. When a cartoon runs fast, he doesn’t realize that he has walked off the cliff and is walking in the air, until he looks down. He only falls down when he realizes that he is no more on the solid ground but in the air. One way to distinguish between opinions and facts are the 5 Ws and one H. The basic difference between Ws and H is,
The 5 Ws (What, Who, Where, When and Why) is the most effective basic information gathering tool for everyone. On other hand H (how) is a challenging question as it requires a level of authority to tell, how did something happen, how something can be done, and especially how should something be done, ... and so on. Usually, the individuals who concern themselves with “how-s” on large scale is considered as “wise-men”. Their roles have declined as scholars in modern society and have become specialized as legislators/politicians as modern scholars are mostly concerned with Ws and seldom talks on H. Having said that still, if you are born in any particular region, your worldview is definitely have been influenced greatly by those individuals whose “how-s” are widely accepted in that region. For instance, if you are born in the West, the “how-s” of Greek philosophers are a great component of your worldviews even if you haven’t read them. Western cultures have integrated those ideas in their values (Democracy, atoms as building blocks of universe, evolution... are few big concepts). Similarly, if you are born in a Muslim society, the “how-s” of the prophets make a big part of your worldview even if you haven’t studied them (Not associate partners with Allah, Obedience to parents should be guided by obedience to Allah, Allah will reply to all human actions, Be patient with what happens to you... etc, are some of the big ideas). Of course, there are other major civilizations with their “how-s” thinkers that have become part of their value system.
Yes, “how-s” are mostly opinions that might have some foundations in Ws, but still if you look them from the perspective of a different civilization, they might look subjects of jokes and might sense only in the form of jokes. In addition, as the world are mostly concerned with facts and evidences so the scholars have mostly limited themselves with Ws. But we can’t ignore the fact that the “how-s” of the past that were products of segregated civilizations and still shapes our worldviews are tearing down societies and creating violence that make heart-breaking headlines almost daily. Now that civilizations are not more segregated, it is time that thinkers also value “how-s” to help reduce the levels of distorted perceptions that we have from other historical civilizations even if their opinions make only sense in the light of jokes.
Occasionally, when it happens that I listen to debates between well-educated and well-versed individuals from different value-systems, I feel one thing very strongly. Neither side appreciate the power of time. The values that each side defend and rationalize with all their logical mights have evolved at least in hundred of years. You can’t expect it to be changed in years. It needs time and plenty of funny “how-s” that “how-s” become identical.