“There’s a kind of Janus-faced nature of some language, so certain linguistic expressions allow for a kind of subjective and objective mixing,” observes Khoo, a

“There’s a kind of Janus-faced nature of some language, so certain linguistic expressions allow for a kind of subjective and objective mixing,” observes Khoo, an associate professor of philosophy at MIT. Sometimes that mixing happens in aesthetics. It also occurs in the realm of knowledge, where modals such as “might,” “must,” and “probably” qualify our certainty about the state of the world. And it often crops up in matters of morality: We may make statements about what we think is right or wrong, then encounter other people with equal certitude but different values.