Last idea, stated up front: sorry for the wall of text that follows!

It's not that I reject the idea of objective reality–far from it. However I do not accept that we can 1) perfectly understand it as individuals, and 2) perfectly communicate any understanding, perfect or otherwise, to other individuals. Intersubjectivity is a dynamical system with an ever-shifting set of equilibria, but it's the only place we can talk about objective reality–we're forever confined to it. I see objective reality as the precursor to subjective reality: matter must exist in order to be arranged into brains that may have differences of opinion, but matter itself cannot form opinions or conjectures.

I'll assume that book or other studies of objectivity lay out the case for some of the statements you make, but as far as I can tell, you are arguing for objectivity from purely subjective stances: "good life", "improper discussion"... and you're relying on the subjective judgement of others regarding your points on objectivity. Of course, I'm working from the assumption that the products of our minds exist purely in the subjective realm... if we were all objective, why would so much disagreement exist? Is it really just terminological? I'm not sure. Maybe.

Some other statements strike me as non-sequiturs or circular reasoning, like "That man has free will is knowable through direct experience". Is this basically "I think, therefore I am?" But how do you know what you think is _what you think_? How do you know those ideas were not implanted via others' thoughts/advertisements/etc, via e.g. cryptomnesia? Or are we really in a simulation? Then it becomes something like "I think what others thought, therefore I am them," which, translated back to your wording, sounds to me something like "that man has a free will modulo others' free will, is knowable through shared experience." What is free will then?

"free will is a priori required for science to be a valid concept" sounds like affirming the consequent, because as far as we know, the best way to "prove" to each other that free will exists is via scientific methods. Following your quote in my previous paragraph, it sounds like you're saying "science validates free will validates science [validates free will... ad infinitum]." "A implies B implies A", which, unless I'm falling prey to a syllogistic fallacy, reduces to "A implies A," (or "B implies B") which sounds tautological, or at least not convincing (to me).

I apologize if my responses are rife with mistakes or misinterpretations of your statements or logical laws, and I'm happy to have them pointed out to me. I think philosophical understanding of reality is a hard problem that I don't think humanity has solved, and again I question whether it's solvable/decidable. I think reality is like the real number line, we can keep splitting atoms and things we find inside them forever and never arrive at a truly basic unit: we'll never get to zero by subdividing unity, and even if we could, we'd have zero–nothing, nada, nihil. I am skeptical of people who think they have it all figured out. Even then, it all comes back to "if a tree falls..." What difference does it make if you know the truth, if nobody will listen? Maybe the truth has been discovered over and over again, but... we are mortal, we die, and eventually, so do even the memories of us or our ideas. But, I don't think people have ever figured it all out, except for maybe the Socratic notion that after much learning, you might know one thing: that you know nothing.

Maybe humanity is doing something as described in God's Debris by Scott Adams: assembling itself into a higher order being, where instead of individual free will or knowledge, there is a shared version? That again sounds like intersubjectivity. All our argumentation is maybe just that being's self doubt, and we'll gain more confidence as time goes on, or it'll experience an epiphany. I still don't think it could arrive at a "true" "truth", but at least it could think [it's "correct"], and therefore be ["correct"]. Insofar as it'll be stuck in a local minimum of doubt with nobody left to provide an annealing stimulus.

I will definitely check out that book though, thanks for the recommendation and for your thoughts. I did not expect this conversation going into a post about Git, ha. In the very very end (I promise we're almost at the end of this post) I love learning more while I'm here!