But Justice Scalia failed to realize that textualism is actually self-undermining. Nowhere does the Constitution explicitly state that textualism, no less originalism or any other method, is the correct theory of constitutional interpretation. Justice Scalia also failed to realize — or at least admit — that textualism and originalism rarely determine a unique outcome for constitutional questions.

The meanings of many words and phrases in the Constitution are not at all obvious. Examples include “right,” “unreasonable,” “probable cause,” “due process,” “excessive,” “cruel and unusual” and “equal protection.” Even if we could find clear definitions of these terms in a dictionary, current or historical, applying these definitions to cases that the founders did not anticipate only expands the range of ambiguity (and therefore interpretive possibilities).

The founders would no doubt sympathize. Because they used flexible, open-ended language like “cruel and unusual” without explaining exactly what they meant, it seems clear that they were deliberately inviting future generations to interpret and reinterpret these words — the very opposite of what textualists and originalists propose.

The founders were not dummies; they knew that society would evolve in unforeseeable ways — morally, socially, politically, technologically — and that this inexorable evolution might well bring about unforeseeable applications of the same words. For example, instead of using the imprecise phrase “cruel and unusual” to lock in any particular punishment (like the death penalty), it stands to reason that they meant it to lock out whatever punishments future generations deemed unconscionable. So true originalism — genuinely following the founders’ intent — requires us moderns to interpret constitutional language in light of our own, not their, moral and linguistic norms.