Thanks for the comment! Very interesting points indeed!
While I do agree that non-utilitarian theories “don’t say” as much as utilitarian theories about positive duties, high priority duties in particular, I partly disagree that non-utilitarian theories “can’t say” much about positive duties or prioritisation.
Instruments like the golden rule or virtues like mercy and compassion may point to similar duties as “moderate” utilitarian theories point out.
To be honest, I was also very sympathetic to utilitarianism overall (saving drowning children from ponds—of course!), but recent “calculus” that point to (exclusive) massive shifts toward invertebrate welfare made me question whether this is a reasonable framework. As the authors of the Moral Weight Project rightly pointed out, they are just the messengers, these are just the results of applying utilitarianism. While I did find the project very insightful, my conclusion was that maybe utilitarianism needs to be questioned.
Lastly, while I understand that utilitarianism takes “human nature” into utility calculus, I don’t think this explains the whole picture. As I tried to explain, this can only function as an “excuse” not a “reason” for action (or inaction). Under utilitarianism (with “human nature” adjustments), people might be “excused” for not dedicating their entire life for invertebrates, but alternative life or career choices of these people cannot be found “reasonable”. I think alternatives can be reasonable (at least equally reasonable as the option of dedication to invertebrate welfare), and these need not be excuses. But these reasons are not to be found in utilitarianism.
Thanks for the comment (and sorry for the late reply)!
My aim was not to ground an ethical framework on common sense ethics alone. My train of thought was:
1- wait, this is so against common sense that it has to be wrong.
2- alternative frameworks are possible and (more) reasonable.
3- these also fit better with common sense judgments too—so this might be a better approach.
So I am not suggesting that we should uncritically follow common sense. I just use it as a test for some kind of “quality control”.
I do agree that utilitarianism seems to be less arbitrary than non-utilitarian theories. But similar levels of arbitrariness can also be found there as well. For example, one can easily justify eating meat (which was your example), if one claims that this increases their productivity just a little bit and allow them to donate more to invertebrate welfare. As a matter of fact, an utilitarian should eat meat under these circumstances even without any regret. Note that many estimates argue that individual diets are inconsequential to a large degree when compared to the impact of even modest donations.
For the incommensurability of values, even if practical wisdom is not the philosophical best move here, there is no “utilitarian” move available since utilitarianism is fundamentally against incommensurability.
Finally, I can imagine that there might be some utilitarian reasons against strongly focusing on invertebrate welfare immediately due to potential backlash etc. But these can only justify actions that “fake” to do something different (say focus on chickens) without changing the real motive of promoting invertebrate welfare in the bigger picture—given that this represents the overwhelming majority of total utility. I am not satisfied with this explanation. I think there are independent reasons that justify genuine actions that do not necessarily focus on invertebrate welfare—but these are not found in utilitarianism.