Although the modern concept of religious terrorism, or indeed terrorism at all, had not yet come into use in the seventeenth century, David C. Rapoport and Lindsay Clutterbuck point out that the Plot, with its use of explosives, was an early precursor of nineteenth century anarchist terrorism.[31] Sue Mahan and Pamala L. Griset classify the plot as an act of religious terrorism, writing that "Fawkes and his colleagues justified their actions in terms of religion."[32] Peter Steinfels also characterizes this plot as a notable case of religious terrorism.[33]