The antonyms for the phrase "argues for" could be "opposes," "contra," or "disagrees." These words describe a person who is against or disagrees with the argument being presented. Additionally, synonyms that could be used for "argues against" may include "refutes," "denies," or "contradicts." These terms describe a person who is actively presenting counter-arguments to the main point being presented. When writing or speaking, it is essential to use language that accurately reflects the intended meaning, and understanding antonyms and synonyms for key phrases can help achieve this goal.