Principle of Proportionality for the Choice Among Legitimate Means for Intervention

Recognising the limits of “therapyTherapy versus enhancement” as the criteria for morality, and considering the previous analysis on the object, intentions, and circumstances of enhancementEnhancement, BioethicsBioethics should propose the conditions for ethical enhancements. An initial idea was developed: a framework that is not based exclusively on the intention to allow or prohibit the use of any means, does not label a means as inherently bad only because they could be misused, and recognises different necessity levels and risk levels associated with the means. The adequate selection among legitimate means for interventions implies proportionalityProportionality: risky means are proportionally permitted to the level of necessity. Therefore, riskier means can be applied for higher necessities, while there is more liberty to use low-risk means. This chapter explains the principle of proportionality and its elements (necessity levels and means risk levels). It then presents examples of applications of the principle of proportionality. Lastly, some clarifications are made, showing the key strengths of this principle, and its consequences for the ethical analysis of enhancementEnhancement interventions.