안이비설신 (眼耳鼻舌身), 곧 보고, 듣고, 맡고, 맛보고, 접촉하는 것과, 색성향미촉 (色聲香味觸), 곧 빛, 소리, 냄새, 맛, 느낌. 그런데 문제는 이들의 만남에서 일체의 번뇌와 고통이 일어난다는 것을 모르고 중생들은 이들을 평생 죽도록 쫓다가 허망한 생을 마친다는 것. 그래서 나온 수행방법 중의 하나가 백골관 (白骨觀). 열반이라는 것을 어렵게 생각할 필요 없다. 아지랑이와 같은 이들을 모두 떨쳐버리고 청정한 우리의 본래 면목인 자성 (自性)으로 돌아가면 된다. 참선이란 이러한 깨달음을 실천하여 확철대오 (廓撤大悟)는 아니더라도 체질화시키는 것

Five roots, or sense-faculties and five sense-objects: Five sensory organs of the eyes, ears, nose, tongue, and physical body; and form, sound, smell, taste, and touch. There is nothing wrong with them for being what they are, but the great problems arise when they associate with each other, which is the fundamental cause of all conflicts and sufferings.
In truth, they are none other than delusions, mirages, bubbles, dreams, and lightning that remain for an instant and then disappear. We must realize that our body is decaying every moment and the final destination of our life is the grave. Hence the practice of observing the skull to realize the evanescence of our life. It is not a pessimistic view of life. It is the vital truth, and realizing this truth is the extinction of all sufferings and the attainment of enlightenment and Nirvana, which is the everlasting peace.