The purpose of this article is to review the meaning of "human beings" as it is used in the Patents Act 1990 (Cth) . The analysis demonstrates that the meaning remains uncertain and that appeals to essential characters and taxonomic conceptions of "human beings" are not satisfactory. The article concludes that the existing qualitative test of what constitutes "essentially human characteristics" (that is not defeated by any technological means of how the "human being" is constituted or created), and the "unlikely to be ephemeral" standard in applying the "contrary to law" exclusion for post-patent grant exploitation limitations, are problematic.