>If a person is incapable of reasoning outside of their class/race/gender/etc position, then how is a fair law even possible?
An entirely fair law might not be possible, at least as long as people with specific class/race/gender interests overwhelmingly influence it. But a somewhat fair law or a law fairer than another, is.
And, at least as I understand it, the scholar doesn't say that nobody is ever "capable of reasoning outside of their class/race/gender/etc position" in general. Just that those making the constitution weren't that good at it.
> Just that those making the constitution weren't that good at it.
They were exceedingly good at it. In my country’s constitution we have all sorts of things from the american constitution, like due process, because we literally have no indigenous words for these concepts.