When people think of “emotion” and “rationality” as opposed, I suspect that they are really thinking of System 1 and System 2 – fast perceptual judgments versus slow deliberative judgments. Deliberative judgments aren’t always true, and perceptual judgments aren’t always false; so it is very important to distinguish that dichotomy from “rationality.” Both systems can serve the goal of truth, or defeat it, depending on how they are used.