religious thought.
    Both the sages of Upanishads and the founders of the unorthodox schools
taught the way of knowledge (jnanamarga), as opposed to the way of works
(karmamarga). Their primary aim was to achieve salvation from the cycle of
birth and death, and to lead others to achieve it. Most of them maintained that
salvation could only be obtained after a long course of physical and mental
discipline, often culminating in extreme asceticism. The basic truths of the
various schools differed widely.
    In many passages of the Buddhist scriptures we read of six unorthodox
teachers, each of whom was the leader of an important body of ascetics and
lay followers. In one passage of the Digha Nikaya short paragraphs are
quoted that purport to give the basic tenets of their systems. A glance at these
will give some impression of the diversity of the doctrines that were
propagated by the ascetic groups of the time.
    The first of the teachers mentioned, Purana Kassapa, was an ‘antinomian’
who believed that virtuous conduct had no effect on a man’s karma.
    The second heretic, Makhali Gosala (Gosala Maskariputra), was the
leader of the sect of Ajivikas, which survived for some two thousand years
after the death of its founder. He agreed with Purana that good deeds did not
affect transmigration, which proceeds according to a rigid pattern controlled
by an all powerful cosmic principle, which he called niyati (fate).
    The third heterodox teacher, Ajita Kesakambalin, was a materialist. The
passage in which his views are given is one of the earliest expressions of
complete unbelief in immaterial categories in the history of world thought.
    Pakudha Kathyayana, the fourth of the six, was an atomist, a predecessor
of the Hindu Vaisesika school, putting forward his theories probably a
century or more before Democritus in Greece developed a similar doctrine of
eternal atoms.
    The fifth teacher, Nigantha Nataputta (Nirgrantha Jnataputra). was none
other than Vardhamana Mahavira, the leader of the sect of Jainas.
    The sixth and last, Sanjaya Balatthipura, was a sceptic, who denied the
possibility of certain knowledge altogether.
    The salvation promised by these teachers, and by others like them, was
not dependent on the mere acceptance of the doctrine or on belief in it on a
logical basis. To achieve release from transmigration it was necessary that the