There is nothing to "prove" here. I mentioned "Occam's Razor" to imply that among competing hypotheses the one with the fewest entities/assumptions is to be preferred. Here that is "life is objectively meaningless" over other competing hypotheses. There is also some inferential reasoning/evidence here since we know that from the pov of the objective Universe our existence on this planet makes not an iota of difference to its functioning i.e. our species could disappear and beyond some local disturbances the Universe will continue its course. That is why i also used the phrase "from the outside in". Note also that the word "Life" is used here in the sense of objective "Existence" since the pov is from external.
The usage (without quibbling too much) of the word "meaning/meaninglessness" is in the commonly understood sense of "purpose/calling/life-objective/etc.". All these are human-defined and therefore "subjective" as life is experienced and lived. There are numerous ways of doing this as is evidenced by the various schools of philosophies/religions/cults/groups etc.
The two viewpoints i.e. 1) Objective view of Life/Existence from the "outside in" vs. 2) Subjective Experiential "inside out" view of Life need to be carefully disambiguated in one's mind.
But we don't have an "outside-in" view? You have an inside + "guess the outside" view. Just because we can imagine an "outside-in" view, it doesn't mean we have it.
If there is an "objective" meaning to our lives which is without recourse to an inside-out view, then we have no access to it.
Occam's Razor, fewest entities/assumptions, etc is so problematic, because it is not invariant to being re-parameterised. I.e. under one description X is more complex than Y, and under another Y is more complex than X.
Here is Roger Penrose talking about the fine tuning of the Universe:
Many use these observations to argue for design. Say it became a scientific consensus that design was the strongest hypothesis, because it just kept making good predictions. Design implies purpose. Would life still be meaningless?
Is this all just a regress to "nothing is just as good as something therefore all life is meaningless"? I think that's where you have to end up to defend Nihilism.
> But we don't have an "outside-in" view? You have an inside + "guess the outside" view.
This is not quite true. There is an Objective Reality consisting of physical laws (invariant in our Universe), Evolutionary evidence explaining the plethora of flora/fauna etc. We are but one species amongst the many that populate this planet. There is nothing "special" about Homo Sapiens (we simply occupy our own niche in the evolutionary tree) except for our different brains resulting in a greater degree of "self-awareness" and more complex social structures than other species.
> If there is an "objective" meaning to our lives which is without recourse to an inside-out view, then we have no access to it.
Not true at all. The whole of Modern Science is founded on trying to find out Objective Reality independent of us and has been quite successful at it.
Huh? It is almost as if you have not read/understood what i had implied w.r.t. Modern Science in my comments above. I had even specifically mentioned "Physical Laws", "Evolution" etc. Notwithstanding the fact that it is our "Consciousness" which "perceives Reality" through "Subjective Experiences" we have managed to remove a whole lot of subjectivity (biases, emotions etc.) through the application of rigorous Scientific Methods to understand a "Objective Reality". All of your Physical Sciences/Technology is proof of that.
PS: In the Samkhya/Yoga school of Hindu philosophy there is a neat assertion which goes - Objective Reality exists because it is common to others besides oneself.
Occam's Razor isn't proof, though. It's a rule of thumb for how to create the most useful hypotheses.
A more complex hypothesis isn't useful until you come up with a method of testing that will distinguish it from the simpler hypothesis. That doesn't mean you have disproved the more complex hypothesis; just that you shouldn't use that hypothesis until you actually have a need for it.
I have already said that there is nothing to "prove" (i.e. no proof) but that it is a necessary corollary of applying the heuristic of Occam's Razor(https://en.wikipedia.org/wiki/Occam%27s_razor).
> A more complex hypothesis isn't useful until you come up with a method of testing that will distinguish it from the simpler hypothesis.
No, the condition is even stronger; a more complex hypothesis should not even be considered until the simpler hypothesis fails for some data/evidence.
The usage (without quibbling too much) of the word "meaning/meaninglessness" is in the commonly understood sense of "purpose/calling/life-objective/etc.". All these are human-defined and therefore "subjective" as life is experienced and lived. There are numerous ways of doing this as is evidenced by the various schools of philosophies/religions/cults/groups etc.
The two viewpoints i.e. 1) Objective view of Life/Existence from the "outside in" vs. 2) Subjective Experiential "inside out" view of Life need to be carefully disambiguated in one's mind.