"[Aurangzeb] summoned the ninth Sikh Guru, Tegh Bahadur (1664-1675 A.D.), to the imperial seat at Delhi and martyred him in cold blood on his refusal to embrace Islam. Some followers of the Guru who had accompanied him were subjected to inhuman torture and torn to pieces. This was as it were a final signal that there was something very hard at the heart of Islam's heart which the Gurus had tried to soften with their teachings of humanism and universalism. Sikhism had to accept the challenge and pick up the sword in defence of its very existence."