>While I agree on the popularity of these terms, I'm not particularly fond of relying on popularity as an argument for or against something of this nature.

I'm not either. I'm commenting on your question of "Why do you assume we live in a reality of "is" and not a reality of "ought?" I am not the person you asked that to, but I figured I'd answer anyways. I am assuming, as I'm sure the other person does, too, that there definitely is an "is" to the world. If I'm making assumptions, I'll assume away the thing that seems the most obvious until I hear something that makes it questionable.

>"the fulfillment of desires" sounds very much like an "ought" to me, not an "is"

When I say desires, I mean it in the broadest, evolutionary sense possible, something like "material, emotions, and stimulation the organism wants/needs/desires for survival, health, and happiness." It's hard to call those things an "ought" because dogs obviously want things, they even need things to survive, but to say the dog "ought" to seek out the game of fetch seems weird, just as it seems weird to say a dog ought to eat to survive, unless you just mean an if/then if it wants to survive, then it should eat. The dog just "is" wanting to play fetch, in the same way my want for equal treatment under the law is a chain of conclusions stemming from my desire to be happy and healthy in the world, and that desire to be happy and healthy just "is" what I desire.

>You talk about the physical reality of "is" being something tangible that we can perceive through our senses... Yet you're also labeling Sally's desires as an "is", which seems to undermine your initial point about "is".

"Ought" arises when one questions what they should be desiring, as in what is a "good" thing to desire. The question pretends that a person is able to control what makes them happy and healthy. People just desire to be happy and healthy, and the nature of what makes someone happy is not under their control, just as the desire to be fulfilled/happy/healthy/survive isn't under their control. It just is a truth or a false that one desires this or that, that ABC leads to XYZ. The "ought" is if one should desire this or that, but that assumes one can control their desires, and I have yet to see a convincing argument for free will.

>While I tend to agree that "ought" cannot really come from "is"

If one means "ought" to mean "if you want this, then you ought to do that", then I think you can craft an "is" from "ought." If you want to solve world hunger, then you ought to do things that further that goal.

>I wonder why everyone assumes that the starting point is "is" and not "ought".

As I said, the reality of the universe seems to really be really real, and there really seems to be some kind of real set of rules that really determines how things play out in this reality. There is no equivalent overwhelmingly obvious set of rules for the "ought reality."

>Because I think "is" can come from "ought". And I also don't think it's terribly challenging to imagine a world originating from "ought" not "is".

I think it's very hard to imagine an "is" that derives from "ought" because if there is no "is" to begin, then there is no "is" to behave how it "ought" to behave. If there is an "ought," which I don't believe really exists, it must be proceeded by an "is" that can do what it ought. Edit: Re-reading this, I guess if we can imagine that "ought" exists somewhere, that there is a 'Higgs boson field of morality' that we just haven't discovered yet, then I supposed it could exist before, after, or come to exist exactly at the same time as everything else.