Few questions are more important than this — Are humans unique? Or, put in other words, is there any basis for human dignity and for treating humans with special respect? It is now frighteningly clear that secular science is inadequate to answer that question.

The May 24-30, 2008 edition of New Scientist, an influential British journal of science, features a cover story that raises this very question. “Human beings are obviously unique,” the headline declares. “But it’s surprisingly hard to say why.” As the actual cover article indicates, there is very little that makes humans “obviously unique.”

The article, written by Christine Kenneally, is truly fascinating. In “So You Think You’re Unique” [available only by subscription], Kenneally addresses the question head-on. “We humans are not as special as we might like to think,” she argues. “Over the past decade, hard scientific fact has steadily chipped away at our supposedly unique qualities, revealing many of them to be just more sophisticated versions of traits found elsewhere in the animal world.”

In making her case, Kenneally explains that scientists have at times argued that humans are unique on the basis of culture, mind-reading, emotions, tool use, morality, and personality. Yet, she goes on to make her case that none of these qualities or capacities is truly unique to humanity.

Concerning culture, she writes:

Art, theatre, literature, music, religion, architecture and cuisine – these are the things we generally associate with culture. Clearly no other animal has anything approaching this level of cultural sophistication. But culture at its core is simply the sum of a particular group’s characteristic ways of living, learned from one another and passed down the generations, and other primate species undoubtedly have practices that are unique to groups, such as a certain way of greeting each other or obtaining food.

In other words, human culture is just a more sophisticated version of what is also found among some animals. She passes along similar arguments about mind-reading (some primates also understand deception), emotions (elephants appear to be empathetic), tool use (some animals use primitive tools), morality (some animals –even rats? — seem to respect moral norms), and personality (“From cowardly spiders and reckless salamanders to aggressive songbirds and fearless fish, we are finding that many animals are not as characterless as we might expect.”).

Finally, Kenneally proceeds to debunk what many scientists have considered the most significant argument for human uniqueness — language. While she holds that humans remain by far the most significantly linguistic animal, she also argues that “other animals clearly do have greater talents for communication than we realised.”

The language issue is central to her consideration, and she pulls together a considerable collection of animal observations. But, even as she makes her case that humans are not unique on the basis of these abilities, behaviors, or capacities, she also brings up five additional arguments for distinguishing humans from other beings.

These five abilities include art (humans alone are capable of representational art), cooking (all other beings fear fire and never cook), religion (“probably not attainable by non-human animals”), humor (“Chimps, gorillas and even rats laugh but, slapstick aside, humour requires language skills beyond the reach of most non-human animals.”), and sport (all social animals play, but sport requires “advanced cognitive abilities.”).

That is about as far as secular science can go.  The methodological worldview of secular science is naturalistic materialism.  Evolution stands at the center of that worldview and evolution can sustain no argument for a categorical distinction between humans and other animals.  What quickly becomes clear is the fact that functional definitions of human uniqueness cannot sustain a claim of human dignity.

On the one hand, these functional criteria fail because they turn out not to be (or are claimed not to be) unique to humans after all.  On the other hand, this also sets up the argument that human beings who fall short of these criteria fall short of human dignity and can be treated as non-humans.  On this basis, Peter Singer of Princeton University argues that infants (who cannot use language) are less morally significant than some pigs and other animals who possess what he claims is a higher consciousness.

The Christian worldview offers the only sustainable foundation for human dignity.  The Christian truth claim, grounded in the Bible, claims that human dignity is ontological (based merely in the human being’s existence) rather than functional.  According to this worldview, every single human being is equally created in the image of God. The other creatures are wondrous and each reveals the glory of God in its own way, but no other creature is created in the image of God.  To be human is to be a bearer of God’s image.  Thus, every single human being possesses full human dignity.

The concept of human rights emerged from the Christian worldview.  Any attempt to ground human rights in a secular concept of human uniqueness is, as we have seen, doomed to failure or fatal weakness.  Current debates about animal rights and even plant rights are symptoms of a dangerous intellectual disease.  The denial of basic human rights to some human beings is tragic evidence that the disease is spreading.

Christians bear a special responsibility to defend human dignity for every human being at every stage of development, and to contend for human rights on the basis of our common humanity.  Christians ground human dignity in the Bible and in the great narrative of the Christian story.  That great narrative tells us that humans are the only beings created in the image of God; the only creature who willfully sinned against the Creator, and the only beings for whom Christ died as Savior.  That narrative, and that alone, can sustain human dignity.

Without that biblical narrative and the Christian worldview that emerges from it, we are left with debates about empathetic elephants and laughing rats.