Samadhi Through Constant Walking 常行三昧. The third
　　   is Samadhi Through Half Walking, Half Sitting 半行半
　　   坐三昧. The fourth is The  Samadhi   Neither  Through
　　   walking Nor Sitting 非行非坐三昧.
　　  
　　   Tso-ch'an and Samadhi
　　  
　　　　  The references above show that several centuries
　　   before the coming of the  Ch'an   schools,  tso-ch'an
　　   already  reached  a  high   state of  development  in
　　   China, both as a practice and  a   scriptural  topic.
　　   These references also show the close association
　　   between  tso-ch'an  and samadhi   in Chinese  Buddhist
　　   practice prior to Ch'an.
　　　　  What is samadhi? Indian tradition  defines  nine
　　   levels of samadhi, each with its identifying
　　   characterisitcs.  For our  purposes, however, we need
　　   only to provide a general definition of samadhi.  If,
　　   through  practice, especially   tso-ch'an, one can get
　　   one's  mind  to a unified   state, this  state  can be
　　   called  samadhi.  To say  that   the  mind  is unified
　　   doesn't  mean that the person  has a sense or idea of
　　   being coextensive with the universe. Rather, it means
　　   that  the  mind  is simply   not moving.  There  is no
　　   distinction  between  inside   and  outside, self  and
　　   environment.
　　　　 There is no sense of time and   space.  There  is
　　   only the sense of existence. So this state of united
　　   mind is called samadhi. This is not a state   of
　　   nothought, or no-mind, since  there   is at least  the
　　   awareness of self experiencing samadhi. It is a state
　　   of  one-thought, or one-mind, and  is not  considered
　　   enlightenment in Ch'an.
　　  
　　   页363
　　  
　　   Roots of Tso-ch'an in India
　　  
　　　　  In most spiritual traditions of India, the yogis
　　   practice  dhyana  to attain   samadhi  at its  various
　　   levels.  After years of austere   practice  as a yogi,
　　   the self-exiled  Indian prince Siddhartha   recognized
　　   that his realization was incomplete. He sat under the
　　   bodhitree  vowing  not to rise until   he had resolved
　　   the question  of death and rebirth.   Only when he
　　   became enlightened one evening, after seeing a bright
　　   star, did  he rise.  He had   become  the  Buddha, the
　　   primal transmitter of Buddhism in our epoch. The
　　   Buddha's experience  became the paradigm of tso-ch'an
　　   practice.
　　  
　　　　   With the rise of Buddhism, two forms of practice