Antonyms for the phrase "take one's side" could include phrases such as "remain neutral," "refuse to take sides," or "remain impartial." These phrases indicate a lack of support for any particular party or position, instead focusing on creating an unbiased environment for discussion and resolution. Other antonyms could include phrases like "oppose," "disagree," or "challenge," all indicating a strong divergence from the position in question. Ultimately, the choice to take or not take a side depends on individual beliefs and values, as well as the specific context in which a decision must be made.