How can we, in our modern scientific world, come to know moral facts? This is a problem of moral skepticism.

Emotivism is a meta-ethical theory that addresses this by challenging the our concept of moral ‘knowledge’. Rather than “X is good” being fact-stating (in the same kind of way “The frog is on the log” is fact stating), moral claims have the veneer of fact-statingness while really having the meaning of statements like “Yay, X!” or “Boo, X!“.