discerning (adj.)

• acute
• apperceptive
• astute
• cogent
• farseeing
• farsighted
• foresighted
• forethoughtful
• gnostic
• incisive
• insightful
• judicious
• knowing
• knowledgeable
• longsighted
• penetrating
• perceptive
• percipient
• perspicacious
• perspicuous
• piercing
• provident
• sagacious
• sage
• trenchant
• understanding