It wasn’t clear which aspect of Catholic dogma you were referring to. Catholic claims about ethics seem to crucially depend on a bunch of empirical claims that they make. Even so, I view such claims as just a subset of claims about ethics that depend on our intuitions.
As above, these conflicting intuitions can only be resolved through a process of reflection. I am glad that you support such a process. You seem disappointed that the result of this process has, for me, led to utilitarianism. This is not a “premature closing of this process” any more than your pluralist stance is a premature closing of this process. What we are both doing is going back and forth saying “please reflect harder”. I have sprinkled some reading recommendations throughout to facilitate this.
The post does not mention whether we have reasons to hold certain things dear. It actually rejects such a framing altogether, claiming that the idea that we “should” (in a reason-implying sense) hold certain things dear doesn’t make sense. This is tantamount to nihilism, in my view. The first two points, meanwhile, are psychological rather than normative claims. As Sidgwick stated, the point of philosophy is not to tell people what they do think, but what they ought to think.
I am always very happy to examine the plural goods that some say they value, but which I do not, and see whether convergence is possible.
Being “agnostic” in all situations is itself a dogmatic position. It’s like claiming to be “agnostic” on every epistemic claim or belief. Sure, you can be, but some beliefs might be much more likely than others. I continue to consider the possibility that pleasure is not the only good; I just find it extremely unlikely. That could change.
I do not think biological and psychological “reasons” are actually reasons, but you’re right that this gets us into a separate meta-ethical discussion. Thank you for the discussion!