Daoist sitting meditation is in some way the source of Tai Chi Chuan. Chang San Feng had his first Chi-experiences while learning the sitting meditation from his master and only later found a way to "put the sitting meditation on two legs."
The principles concerning the body postures are the sames as in Tai Chi. Unlike other meditation practices, daoist sitting meditation is not only about calming the mind and being at peace, it also is a way of cultivating the Chi! Taoist masters believed Chi plays a vital part in spiritual attainment.