concentration and insight [止観] ( shikan): The entire system of meditation set forth by T’ien-t’ai (538–597) in Great Concentration and Insight, the ultimate goal of which is to perceive “the region of the unfathomable,” that is, the unification of the three truths within one’s mind or the three thousand realms in a single moment of life. “Concentration” means focusing one’s mind on one point without any distractions, and “insight” means seeing all things as they are, or perception that penetrates the ultimate reality, or true aspect, of all phenomena.