The word "un-discerning" describes a person who lacks the ability to distinguish between things or make good judgments. Antonyms for this word are "discerning," "perceptive," and "judicious." Someone who is discerning is able to understand and recognize differences, making wise and insightful judgments. Those who possess this characteristic are often referred to as being "perceptive." A person who is judicious has the ability to use good judgment, making decisions wisely and prudently. Therefore, when looking for a person with good decision-making skills, one might seek out someone who is discerning, perceptive or judicious, rather than un-discerning.