The parable your refer to by Sagan I think should be attributed to Antony Flew whose Theology and Falsification is available online. http://www.stephenjaygould.org/ctrl/flew_falsification.html
The parable your refer to by Sagan I think should be attributed to Antony Flew whose Theology and Falsification is available online. http://www.stephenjaygould.org/ctrl/flew_falsification.html