Leon Kass’s Prophecy of a Future That Turns the Stomach

In our relentless pursuit of progress, we have been taught to silence the body’s primal intelligence. We rationalize, we analyze, and we dismiss the visceral churn in our gut as an evolutionary artifact, a primitive ghost in our sophisticated machine. But what if that feeling of revulsion—that involuntary gag reflex in the soul when confronted with certain technological possibilities—is not a bug, but a feature?

Bioethicist Leon Kass argues for this forgotten wisdom, a deep, instinctual knowledge he calls the “wisdom of repugnance.” He posits that this feeling is a profound moral sentinel, an ancient warning system screaming that we are about to violate something sacred about our own humanity, even when our intellect cannot yet articulate the crime.

The Background of a Primal Emotion

The concept of disgust has long been understood as an emotional response that serves protective functions, both for individuals and societies. Experimental studies have demonstrated that disgust can significantly influence moral judgments, with scenarios involving taboo subjects such as incest or corporate fraud eliciting stronger moral responses from individuals who have experienced disgust-inducing stimuli. This phenomenon is aligned with moral foundations theory, which posits that the purity/sanctity foundation, rooted in disgust psychology, evolved to promote hygiene and cultural norms against behaviors perceived as degrading. Such disgust reactions serve as an adaptive heuristic, enabling individuals to intuitively reject actions that may disrupt social cohesion or threaten bodily integrity, even in the absence of explicit genetic knowledge about kinship relations.

In the context of evolutionary biology, disgust is viewed as a mechanism that facilitates pathogen avoidance, allowing individuals to assess risks associated with potentially contaminated substances or situations. Disgust propensity can therefore be regarded as a risk-averse strategy, with empirical findings indicating that higher levels of disgust are often associated with lower levels of risk-taking behavior. This aligns with the view that disgust plays a crucial role in calibrating decisions under uncertainty, particularly in the early stages of risk assessment.

We are afraid to put men to live and trade each on his own private stock of reason; because we suspect that this stock in each man is small, and that the individuals would do better to avail themselves of the general bank and capital of nations and of ages.

Edmund Burke

Historically, disgust has also been linked to societal norms and values, shaping perceptions of what is considered distasteful or immoral. Philosophers like Martha Nussbaum have critiqued disgust-based moral frameworks, arguing that throughout history, various marginalized groups have been unfairly associated with disgust properties such as decay or foulness, leading to dehumanization and prejudice. The Nazis, for instance, used disgust to demonize Jewish people, portraying them as vermin or unclean. As societies have evolved into supersocial entities, the role of disgust has expanded to include social interactions, highlighting the necessity of shunning individuals who violate societal norms linked to cleanliness and health.

Cultural influences on disgust are also significant; what is deemed disgusting can vary widely across different societies. For example, public displays of affection may be considered distasteful in some cultures while perfectly acceptable in others. Nonetheless, certain aspects of disgust, such as revulsion towards feces or vomit, tend to elicit universal responses, suggesting an innate component to this emotion. Scholars, including Leon Kass, have further explored the philosophical implications of disgust, arguing that it serves as a moral compass that guides individuals away from actions perceived as morally reprehensible. In this context, the “wisdom of repugnance” is proposed as a guiding principle that signals instinctual knowledge regarding the boundaries that should be maintained for moral and social integrity.

The Prophet of Repugnance: Leon Kass

Leon R. Kass is a prominent figure in bioethics, known for his advocacy of the “wisdom of repugnance,” a concept he articulated in the late 1990s. His work is primarily centered on the ethical implications of biotechnological advances, including human cloning and genetic engineering. Kass posits that instinctive feelings of disgust serve as a moral compass, guiding societal norms and protecting human dignity against potential dehumanization brought on by technology and cultural shifts.

Historical Origins

Kass’s arguments draw on deep philosophical and religious roots, warning against the hubris and overconfidence that can accompany technological progress. He believes that the visceral horror associated with certain biotechnological interventions—such as cloning—signals violations of the “givenness” of the human body, which are integral to moral identity and ethical restraint.