Table 3 Arguments for and against moral bioenhancement, presented in the reviewed literature

1. Why we (don’t) need moral bioenhancement

There is scope for improvement

Almost by definition, each person can be/act/behave better. We therefore all have a moral duty/imperative/reasons to enhance ourselves. We have good reasons for wanting to better ourselves. Also: a duty to do the right thing.

[1, 2, 4–14]

Human biological nature is defective

Humans are innately evil. Evil cannot be eradicated by socialization and education alone. Or: humans are innately good.

[2, 12, 15–27]

Traditional means are (not) effective enough

Such as education, upbringing, socialization. These will only bring us so far. Or: they do suffice, are attractive and effective.

[2, 15, 17, 19, 21, 26–36]

Our only hope in averting major disaster

Avoidance of ultimate harm. Some of the world’s most important problems can be attributed to moral deficits of individuals. Or: those problems have other causes besides the moral deficits of individuals. Moral enhancement should accompany, or even precede/ prioritize over cognitive enhancement and scientific progress.

[1, 2, 8, 15, 17, 19, 21, 24–29, 34, 36–46]

Moral bioenhancement might reduce criminality

Promise of solving immoral and criminal acts. Or: warning that these are not necessarily the same.

[8, 15, 23, 47]

2. It will (not) be possible to reach consensus on what moral bioenhancement should purport

No consensus on the mechanisms that comprise our moral psychology

The way we should interpret neurobiological findings.

[1, 2, 5, 8, 10, 15, 48–56]

Behavioral changes alone are (not) enough

Emotions versus moral reasoning. Dependent on view on what is considered worthy of moral appraisal. Behavioral control, or: certain attitudes towards behavior are also necessary (they have cognitive content).

[2, 5–8, 11, 12, 15, 17, 23, 29, 31, 32, 34, 44, 46, 48–51, 54, 55, 57–67]

Ethical systems and theories differ and often disagree

Subjectivity of/disagreement between main (substantive) moral theories. Individuals and cultures differ, there is moral pluralism. Possibility of being neutral between different conceptions of the good.

[1, 2, 4, 8, 10, 12, 13, 15, 16, 23, 24, 29, 31, 48, 49, 52–55, 63, 64, 67–69]

(Im)possibility of considerable consensus

The question whether we can find a common ground, despite moral pluralism. Also: discussions on relativism/nihilism, objectivism.

[1, 7, 13–15, 18, 24, 29, 34, 42, 48, 54, 55, 63, 65, 67, 69–71]

Situation- and role-dependency

Situation dependency of what counts as an improvement (morally). Different roles, assessments of situations. Weighing relevant reasons to act. One virtue can turn into a vice dependent on the situation.

[1, 5, 7, 9, 12, 16, 17, 23, 38, 49, 51, 63, 64, 66, 72–74]

Human enhancement versus treating mental disorders

Enhancing humanity or treating mental disorders. Moral element in mental disorders.

[4, 8, 23, 24, 29, 34, 61, 72, 75, 76]

3. The feasibility of moral bioenhancement and the status of current scientific research

Status of current scientific research

Further research is needed or, technological possibilities are already there.

[2, 11, 15, 18, 19, 23, 27, 42, 48, 59, 61, 67, 70, 72, 77]

Complexity of our moral psychology/biology

Makes it doubtful that we will gain sufficient understanding.

[1, 2, 6, 8, 10, 11, 15, 16, 18, 19, 22, 28, 33–35, 37, 42, 48, 49, 53, 59, 61–64, 72–74, 76–79]

Is morality genetically/biologically determined? For example: are virtues and vices heritable? Is the core of our moral dispositions malleable by biomedical and genetic means? Danger of reductionism: we should not overlook the impact of the socio-cultural environment.

Unintended or undesirable side effects

Interventions have effects beyond the intended effects (also: bluntness of the instruments).

[5, 7, 8, 11, 12, 16–19, 22, 23, 29, 30, 34, 35, 42, 46, 50, 51, 60, 62, 63, 69, 75, 77]

A ‘baby and bathwater’ problem.

Moral bioenhancement might even lead to the opposite: not moral progress but moral decline.

Scientific rigor, standards

Research ethical questions about standards of good/sound science. Is scientific experimentation permissible, given that ‘lack of moral virtue’ is not a disease?

[30, 36, 48]

4. Means and process of arriving at moral improvement matter ethically

Other (non-biomedical) methods are preferable

Such as moral training, socialization or (self-) education. Taking a pill might seem ‘all too easy’ or too disconnected from ordinary human understanding. Are biomedical means intrinsically bad? Also: man is not supposed to play God.

[1, 5–7, 9–11, 15–17, 23, 25, 32, 33, 35, 58, 62, 80]

There is no principled difference between traditional and biomedical means

Results matter, the means less so.

[7, 15, 18, 29, 32, 54, 64, 68, 74]

Perhaps the difference lies in the irrevocability/irreversibility of biomedical means.

5. Arguments related to the freedom, identity, and autonomy of the individual

Moral bioenhancement might threaten the freedom of the individual

Moral bioenhancement might impair our freedom and diminish our freedom to act on bad motives. It might subvert moral agency.

[1, 5, 7–9, 15, 17, 20, 21, 28, 29, 42, 44, 49, 51, 55, 58–60, 64, 65, 67, 68, 75, 81, 82]

Moral bioenhancement might endanger our identity and autonomy

Questions about personal identity, and ‘true’ versus ‘brute’ self.

[1, 4, 8, 9, 30, 33, 51, 57, 64, 67, 68, 75, 78, 81–84]

Enhancer decides on outcome of moral bioenhancement (paternalism). Might compromise autonomous, informed choice.

Despite concerns about individual liberty and autonomy, a trade-off is justified

The advantages outweigh the disadvantages.

[1, 5, 20, 21, 29, 42, 45, 60, 67, 68, 74]

6. Arguments related to social/ group effects and dynamics

Moral bioenhancement benefits others

Unlike other types of enhancements (cognitive, cosmetic, sports). Or: who benefits? The individual or society as a whole?

[1, 7, 30, 50, 63, 85]

Moral bioenhancement might foster abuse

Moral bioenhancement might induce free-riding (e.g. prisoner’s dilemma). The virtuous exposed to exploitation by the vicious. It may lead to moral decline.

[1, 5, 8, 9, 14, 15, 22, 31, 33, 42, 48, 56, 61, 63, 64, 66, 76, 79, 86]

Moral bioenhancement might undermine moral diversity and moral debate

It might diminish opportunities for ethical thinking/debate. Reasonable pluralism. Moral bioenhancement might generate social inequalities, elitism.

[4, 14, 23, 31, 47, 48, 53, 54, 61, 63, 71, 74, 76, 79, 85, 86]

Risks of utopian derailing

Progressive, well-intended, yet…

[5, 9, 11, 16, 18, 30, 31, 33, 63, 64, 87]

Utopian.

Interventions will be used recklessly or overenthusiastically. Moral perfectionism.

Mandatory implementation or free/parental choice

State neutrality versus free choice. Danger of tyranny/discrimination.

[2, 9, 13, 15, 20, 21, 30, 38, 39, 44, 45, 48, 53, 54, 56, 63, 66, 68–71, 74, 76, 81, 87]