The Colbert Report aired its final episode on December 18, 2014.1 Nine years earlier, on the first episode, Stephen Colbert coined the word “truthiness.” Truthiness satirized contemporary disinterest in empirical information in a country increasingly “divided between those who think with their head and those who know with their heart.” Truthiness was not just the Merriam-Webster word of the year. Over the past decade, it has been the unspoken mantra of reporters who give equal time to climate science denialists, faith healers, and vaccine refusers. When Justices of the Supreme Court decide questions of scientific or empirical fact—such as whether an IUD prevents or terminates a pregnancy—they increasingly employ fact-finding strategies that equate the empirical evidence (they think with their heads) with the unsubstantiated beliefs (they feel with their hearts). Jurisprudential epistemic relativism (or truthiness) often produces the wrong answer to questions of fact. Issues of law and natural science or human behavior shape many Supreme Court cases, including important recent decisions on death by lethal drug cocktail and the psychological benefits of marriage for same-sex families. At the micro level, decisions that contradict the empirical evidence are inaccurate and unfair to the parties. At the macro level, when judges balance substantiated data against truthiness-based claims, courts distort social perceptions by creating a false epistemic relativism that models poor decision-making and yields bad public policy.