Self-evidently, yes (at least until we find an equivalent alien race with who we can compare notes) but I don't see how any of the remainder of your questions are logical consequences. Clearly by 'man' in the statement we don't mean 'a man' or more specifically 'any old man' but a corrective collective. It's not in any way a justification for the kind of extreme individualism that you're suggesting.

Does that mean that there is a "correct" system? Is it obvious, or has it just yet to be found?

Even if there is something objective.. can't we still just make up whatever story we like, so long as it makes sense, is useful, agrees with what we see in the world, etc?

I'm torn between Stoicism and existentialism as of late. The Stoics have the most comprehensive, attractive system I've found. But, it seems to be based on the idea, "these are the conclusions we've drawn, based on what we see in nature." While Existentialism is more about being authentic and listening to oneself. And actually, that thought of listening to oneself is taught in Stoicism as well. So, perhaps I can be a Stoic existentialist... Why not? there were Christian Existentialists...

Yes and no. We can and do (theoretical physics is pretty much nothing but, for example) and sometimes must simply to survive (the Torah's sanitary laws may be justified by false aetiologies but that doesn't make them any the less sound as guards against disease and sickness). However, there is always a limit to what collectively we can believe and this acts as a powerful corrective. It may take centuries or hours but the literally incredible nature of even the most widely accepted truths has a tendency to out. This role is often claimed exclusively for post-Enlightenment science, of course, but there is clear evidence of it throughout human history.

It does seem odd that people are certain that we can't just choose whatever we like, but also can't suggest what we "should" choose. If we don't know how best to describe reality, then how could one be sure that we aren't justified in just choosing what makes sense to us?

It's like I'm being assured, "you can't just choose what you like"... but it's also acknowledged that no one knows of a system that "should" be followed.

I thought my caveats were pretty good ( so long as it makes sense, is useful, agrees with what we see in the world, etc?). Should I add to them?

It seems to me that we all do have beliefs. Perhaps it makes people uncomfortable to think of it as "choosing" our beliefs? I suppose it is more organic and subjective than sitting down and considering what to believe, at least for many people. Maybe I just had an unusual experience in that I rejected my Young Earth Creationist Christianity, and then went on a journey looking for something else. And then again, I'm conflicted because I'm not sure anyone actually chooses their beliefs. I do feel like I can choose what to explore... what direction to take.

I do applaud the ancient philosophers, especially Plato and Aristotle, in that the tried out various systems, and then changed their minds, and also considered alternatives.

Man is the "measure" of some things. That includes individual persons as well as persons collectively.

There are objective things, too, though.

If we don't know how best to describe reality, — anonymous66

Well, individual persons are the arbiters of that, because "best" is necessarily subjective.

We are the ants climbing the Empire State building frequently totally clueless that we can never grasp our true situation by merely climbing higher. We are using nature to study nature, while the void laughs in our faces. Virtue is its own reward and to have a friend we must first be a friend, to be aware we must first embrace our awareness, to be alive we must first choose to live, to be human we must first open our hearts to ourselves and the world around us. No man is the measure of all things unless he first embraces everything.

I like it.

Its anarchistic Rainbow Warrior philosophy that combines Socratic wisdom with Taoism. We write mathematical poetry and often our poetry is considered the best measure of someone's philosophy. Our poetry uses popular metaphors from Alice in Wonderland to Groucho Marx or whoever and includes a lot of popular music lyrics. We are the world, we are the children of a greater truth and our beautiful words can defy unbalanced gravity itself.

I suppose I do Sound like a relativist.. but I reject that label.

I suppose I do Sound like a relativist.. but I reject that label. — anonymous66

The minute I become perfectly humble I insist on telling the whole world. Perfection is for those who didn't watch the right cartoons.