If you keep reading they give a jury instruction in CA that was held to be constitutional. I posted the full wording above. I think the introduction sentence as follows
Reasonable doubt is defined as follows: It is not a mere possible doubt; because everything relating to human affairs, and depending on moral evidence, is open to some possible or imaginary doubt.
Might not be exactly what some expect.
The court upheld the use of the "moral certainty" language, even while suggesting language that might be less confusing. See my post above for this.
The "moral certainty" language upheld by the Court is the language that I've posted before in several threads (I you all get sick of me posting, tell me and I will stop) in the LaFave hornbook.