• apprehension, approach, cognizance, comprehension, conception, conceptualization, perception, school of thought, sentiment
• apprehensive, quick of understanding
• frame of mind, slant of life
• acumen, quick wits, wit
• apt, bright, nimble, nimble-minded, nimble-witted, quick of understanding, smart
• blockish, blunt-witted, dull-witted, pokey, poky, thick, weak-headed
• to be of the opinion that
• to hold extreme opinions
• to hold extreme opinions