In the 1960s Schaeffer read the works of Reconstructionist theologian Rousas John Rushdoony with appreciation, and according to Barry Hankins, "it is quite likely that Schaeffer's belief that the United States was founded on a Christian base came in part from Rushdoony." Schaeffer later lost this fervor because Rushdoony was a postmillennialist (holding the doctrine that the kingdom of God will be built on earth before the second coming of Jesus) while Schaeffer was a premillennialist (holding that the kingdom of God will only be ushered in with the second coming). Further Schaeffer thought that Rushdoony's system would require a merger of church and state, which he opposed. He held that the principles, not the actual details, of Old Testament civil law were applicable under the New Covenant of Jesus. He wrote "The moral law [of the Old Testament], of course, is constant, but the civil law only was operative for the Old Testament theocracy. I do not think there is any indication of a theocracy in the New Testament until Christ returns as king."