While it's certainly true that we don't have a complete understanding of nature, I think we can safely assert that dead things don't feel, and I'm completely unaware of any evidence to the contrary (and I would think its existence would be quite noteworthy).

I don't think we need to call it a "belief" anymore than we need to say Russel's Teapot not existing is a "belief." We certainly could go down that route, but then virtually everything becomes a belief and we're left with a much less meaningful term.

I kinda feel like this argument is similar to an nihilist telling a logician that nothing is true.