There is a Haiku blog post, in By John Lina, entitled Do or Die, that asserts philosophy to be (a) subjective and (b) opinion. All of our rules are subjective and based on opinion; religion, law, and even the boundary lines. There have been a great many people, and animals for that matter, put to death as a result.
The two basic extant philosophies (opinions) are atheistic and religious, that there is, or isn't, an immaterial world. Many members of the scientific community are of the opinion that there is not. All of those in the religious community are of the opinion that there is. Who is right? And if one is right, is the other wrong. This schism is a good example of my assertion that opinion rules.
In the above example both sides use their opinions as a basis for action. On both sides there are nuances. On the scientific, or atheistic side, mathematics and experimental research support assertions. As reliable as these are, there are instances where experience has proven them wrong, or inadequate. Conclusions based on the scientific method are eroded by experience. It is, however, to their credit that when proven wrong, it is admitted and a new understanding is reached.
The other side, the religious, is less inclined to ever admit to later, better conclusions. The nuances on that side are numerous, with the major religions leading the way, followed by sub-sects within them ranging in size from very many to a few adherents. It is in these sub-sects that, what are thought to be refinements, are made.
The opinions of all are born in imagination, which is highly developed in humans. It was sparked somewhere in history, and Sumerians are the oldest identified humans who demonstrated highly developed imaginations. That would have been about 3000 BC. And there may be other, older examples. The quest for the origins of our enhanced capabilities goes on, and it is to our credit that it does. There seems to be a need to satisfy our curiosity about origins.
In any event, we are governed by opinions. We uphold, protect, and defend them, sometimes to the detriment of others, who may have conflicting opinions. We should not lose sight of the fact that it is all opinion. And, perhaps, because there are so many, we can conclude that not one of them is totally correct. We are reminded of the three blind men describing the elephant.