a final theory holds that "the three strategies" dates from the late west han dynasty (206 bc - 9 ad), around the year 1 ad, and that it is a product of the now-extinct huang-lao school of daoism. this theory assumes that the work transmitted to zhang liang was not the present "three strategies", but was actually "the six secret teachings". (the work presently known as "the three strategies of huang shigong" was supposedly known as "the records of huang shigong" until the sui dynasty, accounting for this confusion). according to this theory, the late composition date accounts for the numerous references to political circumstances (powerful families usurping power; government affairs in an age of peace; and, philosophical syncretism organized around huang-lao concepts) and the advanced use of characters found in the text. in the absence of contrary archaeological evidence, many modern scholars consider this final theory to be the most probable.