四度加行

Special study of or advancement in the four degrees, a method of the esoterics, formerly extending over 800 or 1, 000 days, later contracted to 200. The four 'degrees ' are [lang id =1028]十八道, [lang id =1028]胎藏, [lang id =1028]金剛, and [lang id =1028]護摩, but the order varies.