Plato, Descartes, and Human Exceptionalism

Posted by Sherry F. Colb

In my Verdict column for this week, I explore the implications of Plato's allegory of the cave, along with his distinction between Platonic "forms" and mere exemplars, for human relationships with animals as well as with one another.  I recommend reading the column, because the ideas in it are difficult to summarize in a sentence.  Here, though, is my attempt at summary:  I argue that describing an idealized abstraction of an object (or a living subject) as reality, as Plato does, while relegating material objects (and subjects) to the status of mere exemplars of that reality, creates a moral risk of subordinating and even obliterating the inherent value of the individual humans and non-humans with whom we share this planet.  I use the occasion of the fortieth anniversary of the Endangered Species Act (ESA) to consider the difference between attending to an individual's inherent value, and attending to an idealized category (such as race, sex, nation, or species) while ignoring the worth of the individuals who occupy that category.  The ESA, for reasons I explain in the column, approaches animal species as forms rather than attending to the individuality and interests of particular animals.  This is why the extinction of a species (rather than the death and suffering of particular animals) is the target of the ESA.

After I described my column to fellow columnist Professor Dorf, he responded that he could see a direct line from Plato to Descartes.  I had not thought about this line, but I am convinced that he is correct about this. Descartes is most famous for the inference he drew that "I think, therefore I am."  This inference, like Plato's allegory of the cave, elevates ideas over reality by positing that the first and most elemental thing we can know as truth is that we can cogitate and that it is this capacity to think (in the particular ways in which we humans think) that manifests and proves our existence.  In an interesting (and quite unpersuasive) effort to prove the existence of God, Descartes suggests that God must  exist  because we can imagine a perfect being, and one of the necessary features of a perfect being includes its actually existing (as though existence were a trait, like height or weight).  Based on Descartes' way of thinking about reality, it is not all that surprising that Descartes would believe that one could prove the existence of something (or someone) by reference only to one's imagination.

I realize that I am not being entirely fair to Descartes.  For one thing, he showed tremendous insight in implicitly intuiting that everything we believe to be true about the world is necessarily processed through our own sensory and mental processes.  At some level, all we really know about the world is our own brain's reactions to stimuli in the world.  Descartes' deep moral error, however, makes itself known when he speaks of nonhuman animals (and thereby colors my view of his mind/body division more generally).

Descartes argued that only humans can have subjective experiences and that animals are simply animate machines that appear to have experiences, much in the way that a clock that chimes at noon might appear to "know" that it is noon but is in fact incapable of feeling or knowing anything.  Carrying his conclusion about animals' insensate qualities from the world of ideas into the material world, Descartes performed shockingly cruel experiments on live, conscious animals, arguing that their cries signified nothing and that suffering was impossible for them.  The reason for Descartes' bizarre belief that animals lacked sentience was that because he imagined that animals lacked "souls," he concluded that they were simply matter without minds, and in the absence of a mind, a creature is incapable of experiencing subjective states like pain and pleasure.  He and his followers accordingly nailed live, conscious dogs to wooden boards and sliced into them to observe their internal organs at work.

Though Descartes' beliefs about animals would sound insane to most people today, many have nonetheless continued to draw a firm moral line between human and nonhuman animals, arguing that something "unique" about humans entitles humans (but not animals) to freedom from torture and slaughter and also entitles humans to exploit animals in ways that involve (even more than in Descartes' day) the infliction of torture and slaughter upon animals.  What is this supposedly "unique"  trait?  When described by those asserting that humans are "unique" in some morally important way, the answer is usually something about our particular kind of intelligence, tracing to the special "mind" enabled by our large/complex/unique brain.  Like Descartes, then, those who subscribe to this view of human uniqueness elevate the human mind and its capacities to justify harming other animals.

Likewise, the view that it is morally acceptable to consume the products of animal torture and slaughter (including the flesh and secretions of animals) frequently entails the proposition that animals lack the human "mind" or "soul."  Animals' experiences of suffering and death, though generally acknowledged to exist, therefore do not have moral weight to counterbalance people's desire to eat dairy cheese, an omelette, or a piece of meat, instead of nut-based vegan cheese, a vegan frittata, or a spicy plate of rice and beans.  This proposition would be familiar and sympathetic to Descartes.

Both Plato and Descartes emphasized abstract thinking as the key to discerning the truth, and abstract thinking appears to be a human specialty.  I would suggest, though, that our modern and more enlightened view of those incapable of abstract thinking (including infantile and some mentally disabled humans) would help expose as false the nonsense propagated by Descartes and still with us, in a less obvious form:  the notion that anything "unique" about some subset of the human population justifies the ongoing harm that we inflict on animals for our own purposes.