John D. Barrow and Frank J. Tipler, The Anthropic Cosmological Principle (Oxford: Clarendon Press, 1986). Although the writings of Dyson and Tipler are recent examples and have received wide discussion, they actually represent recent variations on a century-long series of proposals that follow on similar questions. See Barrow and Frank J. Tipler, The Anthropic Cosmological Principle, Chs. 2-4. for an excellent introduction. See also Mark W. Worthing, God, Creation, and Contemporary Physics, Theology and the Sciences Series (Minneapolis: Fortress Press, 1996), Ch. 6. for a briefer summary.