with Armstrong, S. , ÓhÉigeartaigh, S. , 2015, Outrunning the law: extraterrestrial liberty and universal colonisation, in C. S. Cockell (ed.), The meaning of liberty beyond earth, Dordrecht, Springer, pp. 165-186.
with Earp, B. D. , Savulescu, J. , 2012a, 'Natural selection, childrearing, and the ethics of marriage (and divorce): building a case for the neuroenhancement of human relationships', Philosophy & Technology 25 (4), 561-587.