The antonyms for the word "un-discriminating" are discerning, discriminating, selective, and particular. These antonyms all describe someone who is careful and thoughtful in making choices and does not act without careful consideration. While un-discriminating might suggest a lack of bias or prejudice, these opposite terms indicate a person who is not easily swayed by superficial appearances or hasty judgments. They evaluate situations and people objectively, taking into account all relevant factors before making a decision. In this way, they demonstrate wisdom, insight, and a commitment to fairness and justice.