Language use caution

[Twizelby]

We have all been there. You don't choose your words quite carefully enough then you get trapped and they get their brains stuck on what you previously said. I caution you to say "there is no evidence that plants are sentient" rather than "plants are not sentient." the first puts you in the position to be atheist agnostic about plant sentience and other kind of sets you up as making a positive statement. Then you get stuck being asked to prove something is not sentient. "prove this raisin is not sentient"

[Volenta]

Don't see it as a problem to make a positive statement about it actually... There is no central nervous system, so how could they be sentient? There is absolutely no place for plant sentience in our current scientific understanding.

Not everything you are not 100% certain about—and I would argue that 100% doesn't even exist—should be stated like your agnostic. I suppose you're also not doing that about evolution, gravity, existence of atoms, etc. If it's beyond reasonable doubt, I think you're allowed to state it like it's a fact. We could argue about whether plant sentience actually fit into this category if you wish.

[Twizelby]

I have no problem with saying plants aren't sentient I'm just saying that if you are in a debate that you can be asked to prove the positive assertion that plants are not sentient. Plants have no nervous system isn't really proof unless someone makes the assertion that they do have sensory organs.

[brimstoneSalad]

If it's beyond reasonable doubt, I think you're allowed to state it like it's a fact.

Yep.

But if you want to add conditions after the fact, if they challenge you, say it follows from scientific naturalism (Material reality, and evolution).
If they reject those things then they are asserting that plants are magically (literally supernatural magic) sentient.

It's not a proposition that needs to be taken seriously. And because there's no evidence for it, is it not moral to consider it, and you wouldn't be responsible for it because it was literally impossible to know.