B.C. on, but which may have been in existence earlier, adopted the
politico-scientific ideas of Tsou Yen's school. Such secret societies
have existed in China down to the present time. They all contained a
strong religious, but heterodox element which can often be traced back
to influences from a foreign religion. In times of peace they were
centres of a true, emotional religiosity. In times of stress, a
"messianic" element tended to become prominent: the world is bad and
degenerating; morality and a just social order have decayed, but the
coming of a savior is close; the saviour will bring a new, fair order
and destroy those who are wicked. Tsou Yen's philosophy seemed to allow
them to calculate when this new order would start; later secret
societies contained ideas from Iranian Mazdaism, Manichaeism and
Buddhism, mixed with traits from the popular religions and often couched
in terms taken from the Taoists. The members of such societies were,
typically, ordinary farmers who here found an emotional outlet for their
frustrations in daily life. In times of stress, members of the leading
_élite_ often but not always established contacts with these societies,
took over their leadership and led them to open rebellion.

The fate of Tsou Yen's school did not mean that the Chinese did not
develop in the field of sciences. At about Tsou Yen's lifetime, the
first mathematical handbook was written. From these books it is obvious
that the interest of the government in calculating the exact size of
fields, the content of measures for grain, and other fiscal problems
stimulated work in this field, just as astronomy developed from the
interest of the government in the fixation of the calendar. Science kept
on developing in other fields, too, but mainly as a hobby of scholars
and in the shops of craftsmen, if it did not have importance for the
administration and especially taxation and budget calculations.