John is characterized as logical and science-minded based on his practical approach to life, skepticism about superstition, and his preference for tangible, provable things.
In paragraphs 6 and 7, John is characterized as logical and science-minded. This characterization comes from various descriptions of John's interactions and thoughts. For instance, when considering why the mansion they have rented for the summer is so cheap, John dismisses any superstitious reasons with practical explanations. This is further supported when John's practicality is described, indicating he has no patience with faith and scoffs at superstition, favoring things that can be quantified and proven. The references to his reactions to the wallpaper, his indulgence in his wife's fears only to a certain practical extent, and the fact that he is wise and loves his wife, despite not always understanding her struggles, all point to a character that is grounded in reality and guided by logical thinking.