guess it describes a person who is used to critical thinking. Of course, if one thinks critically, one would ask what "critical thinking" really means. There are so many definitions and descriptions. My favorite one is "The habits of mind that characterize a person strongly disposed toward critical thinking include a desire to follow reason and evidence wherever they may lead, a systematic approach to problem solving, inquisitiveness, even-handedness, and confidence in reasoning." 其实我觉得就是“实事求是指导下的打破砂锅问到底”。