Abstract

Many would intuitively agree with the claim that human morality is complex. I will formalise this claim, give three strong reasons for believing in it, address objections and tentatively list consequences of the unusual complexity of human morality. I will argue that a proper account of human moral traits will have an unusually large degree of complexity. I will present as support for this claim the intricate causal history of moral traits, their propensity to paradoxical effects and various epistemic difficulties. The complexity of human morality has bleak consequences for hopes of manipulating our moral traits using biomedical interventions, be it in the treatment of diseases or in the prospect of fixing our moral failings.