The antonyms for the phrase "more irrationally" are based around the idea of rational thinking, logic, and reason. Some possible antonyms for "more irrationally" include: more logically, more reasonably, more sensibly, more thoughtfully, and more judiciously. When someone is acting in a more rational manner, they are making decisions based on sound reasoning and logical thinking. Conversely, when someone acts more irrationally, their decisions may be based on emotions, gut instincts, or biases. It's important to be aware of these antonyms and strive to make decisions using rationale and logic, rather than succumbing to knee-jerk reactions or illogical thinking.