It depends on whether those justices have studied
THE CONSTITUTION
or
“Constitutional Law”.
The latter is a study of what judges have said the Constitution means, instead of what it originally actually meant at ratification.
That is a good point. I know that when I was in Law School reading the Constitution was not a requirement of my Constitutional Law classes. I was required to read Supreme Court "Opinions" on what the Constitution said, but at no time were were ever required to read nor were we ever tested on the actual language of the Constitution.