Ethical issues implicitly permeate all aspects of patent doctrine, including definitions of invention, novelty, inventive step, utility, disclosure and so forth. Interestingly, and in addition, many patent systems allow explicit ethical objections. This is most notable in the European Patent Convention (‘EPC’) which states at Article 53(a) that: ‘European patents shall not be granted in respect of inventions the commercial exploitation of which would be contrary to “ordre public” or morality.’In broad terms, this provision means that patent protection is denied to immoral inventions, no matter how novel or inventive the invention may be. Intriguingly, it requires lawyers (including patent examiners and judges) to define morality. Recent cases concerned the morality of commercially exploiting mammals genetically programmed to develop cancer (Harvard Oncomouse) and stem cells obtained from human embryos (WARF and Brustle). These raised difficult questions about genetic engineering, animal experimentation, the moral status of embryos, the morality of patenting animals and parts of the human body. With such troubling ethical issues in the frame, it is not surprising that Article 53(a) itself has proven highly controversial. The principal difficulty is how to implement such a rule. How does a patent examiner or court assess whether an invention is immoral to the point that, unlike other inventions, it should not be granted patent protection? It is a question that runs headlong into the complex intersection of law and morality or, put another way, the intersection of intellectual property and philosophy. Section III explains some of the contentious issues in the interpretation of Article 53(a). In light of these issues, many authors and patent practitioners have thrown their hands in the air in frustration, suggesting that the problems are insurmountable and that patent law would be better off abandoning the explicit morality exclusion. In the meantime they tend to interpret the provisions in a highly legalistic and usually narrow way, dissecting the words of the statute in fine detail. Often the words might be ascribed more than one meaning, but alternative interpretations are swept away for a legally plausible, but normatively doubtful, reason leaving the decisions mired in controversy and cast adrift in interpretative uncertainty. In contrast there is very little discussion of what might be the jurisprudential underpinnings of a morality exclusion in the patent system. This is considered briefly in Section IV and leads into the main contention of this chapter.The principal argument is that a better appreciation of the nature and purpose of the immorality exclusion provides some vital clues as to how it should be interpreted (Section V). More specifically, it will be argued, building upon Burk and Lemley’s seminal paper in 2003, that the explicit morality exclusion is a ‘policy lever’, similar to the thirteen already identified in their paper, which tailors patent law to its overarching utilitarian objective of promoting socially beneficial inventions in a manner compatible with fair and just social organisation. As such, the explicit morality provision is a valuable opportunity to optimise patent policy, and an advisable inclusion in all national patent systems. Countries like the US which lack an explicit morality provision are disadvantaged by its omission. The exclusion calls for policy analysis, which requires more normative input by judges (and patent examiners) than linguistic textual analysis, but considerably less than a search for moral truth. It is thus well within the ordinary duties and capabilities of skilled legal decision-makers, who appreciate that law sensibly leaves discretion for judges (and other decision makers) to develop and shape the law in ways that promote desirable goals and behavior. This is not to say that this is how the immorality exception has been used to date, but rather how it could be used in the future. Sections V and VI also discuss some of the implications of seeing the explicit morality exception as a policy lever. Section V revisits the debates in the literature, and Section VI considers the topical issue of embryo stem cell patents. These comments are necessarily general rather than detailed or prescriptive. More definitive answers require a more fine-grained case-by-case analysis, which the judiciary and examiners would need to tackle in any given case. And although it might be tempting to argue that judges and patent examiners should not be given such an active role in shaping economic and social policy, the fact is that they are doing it at the moment, and it would better that they do it consciously and critically, rather than inadvertently or furtively.