2008 • 66 Readers • 335 pages • 3.8
2018 • 112 Readers • 328 pages • 4.1
#4 of 4 in Language and Human Nature Tetralogy
#1 of 3 in Civilizations Rise and Fall
#3 of 3 in Civilizations Rise and Fall
2019 • 105 Readers • 502 pages • 3.6
1 Reader
#1 of 2 in What If?
2005 • 327 Readers • 323 pages • 3.9