In an article titled “Why Not Physician-Assisted Death?” from the medical journal Critical Care Medicine, Constantine A. Manthous writes, “Our collective repudiation of physician-assisted death, in all its forms, has complex origins that are not necessarily rational.”

Manthous proposes that the strong negative responses to physician-assisted suicide (PAS) and euthanasia “are moral intuitions, without rational foundation, predicated on inherited, self-preserving neurocircuitry.”

In summary, he argues that repulsion to euthanasia and PAS come from evolutionary instinct for survival. Furthermore, since this “moral instinct” has been within us for so long, we now have an ingrained dislike for even the words used in talking about such things. So, when we hear words like “euthanasia” or “physician-assisted suicide,” our knee-jerk reaction is to reject them.

But what about religious prohibitions? Manthous employs a two-fold argument here by first stating that the “holy books of the major religions are relatively vague about hastening the death of another.” In other words, religion doesn’t make a clear-cut prohibition against such actions. But if you are not convinced by that argument, Manthous later comes back and argues that “States and religions are human constructs,” and that “they to varying degrees institutionalize our neurocognitive heritage—reflect our hard-wiring.”

So, if you are one that argues against PAS or euthanasia on the basis of texts like the Scripture or the U.S. Constitution, Manthous argues that the texts fail to speak clearly to the issue, and even if they did speak clearly, they are just man-made documents based on our evolutionary progression up to this point in human history.

When Manthous says, “My thesis here is that our repudiation of PAS and euthanasia is a moral intuition, without rational foundations,” we understand that his use of the phrase “moral intuition” is best understood to mean evolutionary biological. For Manthous, “moral intuition” does not imply any objective point of reference—creator, special or general revelation—it is simply the result of our “neurocognitive evolutionary legacy.”

In the section, “Toward a Solution,” Manthous finds hope that humanity can continue progressing and find PAS/euthanasia as acceptable in some cases. He thinks that the solution may be found in changing some of the words, even quoting Noam Chomsky as support for the idea that these issues merely come down to language and verbal games.

Manthous closes with this: “Words trigger neurologic phenomenon that correlate to moral tenets. In this way, deliberations might benefit from alternative terminology, say, ‘physician-assisted death for irreversible suffering.’”

This article is important in helping us to see the direct linking of evolutionary-grounded moral psychology and the acceptance of PAS and euthanasia.