Describes a person, attitude, or approach that is intellectual, rational, or cerebral, often contrasted with emotional or practical orientations.
He solved the problem with an intellectual approach.
The discussion was too intellectual and difficult for ordinary people.
理性的 means 'rational', emphasizing logic and reason; 主知的 leans more toward intellectualism or a cerebral orientation.
Compound of 主 (しゅ, 'main, primary') + 知的 (ちてき, 'intellectual'). The exact historical derivation is uncertain, but the word follows a common pattern for forming adjectival nouns.