The controversy surrounding the work of Charles Darwin is a moral and political debate as well as a scientific one. A year ago last December it was brought before the Supreme Court of the United States, which heard oral argument about a Louisiana law that requires the teaching of Creation science in any public school where Darwinian evolution is taught. One of the lawyers, arguing that this law was an unconstitutional establishment of religion, offered as evidence a quotation from the legislative testimony of one of the law’s supporters, who had said:
I think if you teach children that they are evolved from apes, then they will start acting like apes. If we teach them possibly that they were created by almighty God, they will believe they are creatures of God and start acting like God’s children.
Henry Morris, one of the leading proponents of Creation science, has warned:
Evolution is the root of atheism, of communism, Nazism, behaviorism, racism, economic imperialism, militarism, libertinism, anarchism, and all manner of anti-Christian systems of belief and practice.
He may have exaggerated the danger somewhat. But even Friedrich Nietzsche warned of the nihilistic consequences of Darwin’s teaching as a doctrine that he considered “true but deadly.”
The deadliness of Darwin’s teaching seems evident, for example, in the way it apparently subverts the natural rights teaching of the Declaration of Independence. Thomas Jefferson appeals to the “laws of nature and of nature’s God.” But Darwin seems to teach us that, by the laws of nature, we are just one life form among many, with no natural end or purpose except to survive and reproduce. Jefferson claims that human beings are naturally equal in that they are endowed with a special dignity that naturally entitles them to certain rights. The reasoning behind this thought, which could be found in the works of Aristotle, Cicero, and Locke, is that human beings are equal in their worth as human beings, who are set apart from and above all other animals by virtue of their rationality. But Darwin denies that human beings are different in kind from other animals. Thus Darwin seems to force us to confront the abysmal thought of nihilism: that there is no rationally discoverable standard in nature for giving moral weight to human life.
I would argue, however, that a proper interpretation of Darwinian biology still permits us to look to nature as a source of standards for human life. The tradition of natural right has always rested upon a biological foundation. Thomas Aquinas speaks of the natural law as the law nature has given to all animals. And Aristotle supports his conception of natural right with biological claims. I believe a comparison of Aristotle’s biological writings with those of Darwin would suggest that Aristotle’s biological understanding of natural right is still defensible even in the light of Darwin’s advances. But Michael Ruse’s Taking Darwin Seriously reminds us that many of Darwin’s contemporary supporters would not agree with me.
Nevertheless, I think Ruse’s book is one of the best ever written to help us think through the implications of Darwinism for political philosophy. (Among recent books, I would also recommend Leon Kass’s Toward a More Natural Science, Hans Jonas’s The Imperative of Responsibility, and H. Tristram Engelhardt’s Foundations of Bioethics.) My disagreements with Ruse do not lessen my respect for his arguments, because for me they serve as instructive provocations.
Ruse’s defense of Darwin is not as instructive as it might have been, however, if he had seen that to take Darwin seriously we must also take the Bible and Greek philosophy seriously. Prior to the modern era, Greek rationalism and biblical revelation were the two great sources for explaining the meaning of human existence. The founders of early modern science (such as Descartes and Bacon) sought a third alternative grounded in scientific methodology. Darwin seemed to fulfill that project by explaining the origin of all living beings through the scientific method without reliance on either philosophic speculation or biblical faith.
I would agree with Ruse’s claim that Creation science is not genuine science. (The case for this conclusion has been argued well by Philip Kitcher in Abusing Science.) But Ruse is wrong to assume from this that the Book of Genesis poses no serious challenge to the Darwinian scientist. To be taught that in the beginning God created the heaven and the earth is to face the incomprehensible mystery of the origin of things, and thus to recognize the limits of human reason. Modern science cannot remove that mystery by teaching that everything evolved from a universal starting point. If it is incomprehensible that God created everything out of nothing, it is no more comprehensible that nothing turned itself into everything.
It is surprising that Ruse casually dismisses the biblical understanding of things, but it is even more surprising that he ignores the tradition of Greek philosophy. In particular, one would have expected that a book on the philosophic implications of biology would give some attention to Aristotle, who remains perhaps the greatest philosophic biologist. Aristotle’s biology manifests the teleological understanding of nature as purposeful, with human beings, as the only fully rational animals, being the highest embodiments of nature’s purposes. That living beings act for the sake of ends, as if these ends were conceived in the mind of a cosmic artist, is for Aristotle a fact of observation. Yet it is a fact that he never tries to explain fully. The idea that nature had immanent causes analogous to those of a conscious artist remains mysterious. Equally mysterious, in Aristotle’s account, is the capacity of the human mind to understand nature. If we believe anything at all, we must believe in the validity of rational thought as a grasping of reality. But rational thought, particularly at the level of intellectual intuition, cannot be fully explained, although it is itself the precondition for explaining anything at all.
So, despite their critical disagreements, the Bible and Aristotle agree that in pondering the fundamental mystery at the core of things, absolute knowledge is unattainable. The Socratic philosopher seeks for knowledge of his own ignorance. The pious believer seeks for faith as “the substance of things hoped for, the evidence of things not seen.” One speculates on the mystery. The other worships it.
Darwinian evolution does not necessarily supplant either the Bible or Aristotle. Darwin himself suggested that evolution arose from “the laws impressed on matter by the Creator.” And he welcomed the argument of Asa Gray and Thomas Huxley that his theory of evolution vindicated the idea of natural teleology. Ruse, however, rejects, at least implicitly in this book, any such reconciliation of Darwinian evolution with Aristotelian teleology or biblical revelation. Instead of that, he tries to unite Darwinian biology and the philosophy of David Hume. But he cannot do that without falling into nihilism.
Nonetheless, I would consider much of what Ruse argues as a Darwinian confutation of Aristotle’s biological understanding of human nature. For example, Ruse points to the human capacity for language to illustrate how our biological nature shapes our cultural conventions. The human vocal tract, unlike that of the apes, is specially adapted for speech. Although the vocal organs do not dictate any particular language, they do determine the basic patterns found in all languages. And since language is the fundamental tool of culture, we must conclude that the human capacity for culture is grounded in the biological nature of human beings. All of this sustains Aristotle’s biological observations about the importance of language: human beings are by nature the only political animals because, although other animals have some ability to communicate, only human beings are capable of the articulate speech through which they reach a shared understanding of those moral concepts that constitute a political community.
Presumably Ruse would reject Aristotle’s thinking insofar as he represents “traditional philosophy and theology.” The traditional view of human beings, as Ruse explains it, is that although we are animals, we are special animals.
We have some special essence, which gives us a favoured place in this world and (perhaps) the next. This distinctive part of human nature is our rational faculty, or some such thing—that which enables us to see the truth about the world and about the proper courses of action binding upon us humans. (pp. 103-4)
But “if you take Darwin seriously,” Ruse insists, you must reject this. “Any powers we have are no more than those brought through the crucible of the evolutionary struggle and consequent reproductive success.” Ruse’s position becomes self-contradictory, however. If taking Darwin seriously means recognizing the truth and worth of what Darwin teaches, then we cannot take him seriously if he teaches us that we have no power to see the truth or worth of anything.
According to Ruse, Darwinian biology, in both epistemology and ethics, supports the arguments of Hume—that is to say, it requires a denial of “metaphysical reality” and an affirmation of “common-sense reality,” which means a denial of objectivity and an affirmation of subjectivity.
In epistemology, we normally think that the reality of common sense, the reality which we have truly had a role in creating (not choosing!) is the human-independent reality of the metaphysician. In ethics, we normally think the morality of common sense, the reality we have truly had a role in creating (not choosing!), is the human-independent morality of the objectivist. But they are not. (pp. 269-70)
Ruse maintains that the fundamental principles of human reasoning are innate in the human mind because they were favored by natural selection. Those primeval human ancestors who respected the law of the excluded middle, who avoided contradictions, and who knew how to count, were more likely to survive and reproduce than those who did not. Similarly, the innate sense of obligation that underlies morality could have evolved to promote biological ends. Those who felt they ought to help their relatives and neighbors, who felt that killing innocent people was wrong, and who thought no one should ever commit incest, enhanced their biological fitness.
But although both the rules of thought and the rules of morality have evolved as innate dispositions only because they serve biological ends, and not because they are objectively true or necessary, we must believe them to be objective; and thus we are unconscious of their biological origins. Rationality and morality as biological mechanisms work best for human beings when the mechanisms are concealed by the illusion of objectivity.
Ruse concedes, however, that although both reason and morality originated as biological adaptations, their cultural applications transcend their biological origins (pp. 149, 206, 223). Yet he never works out the implications of this for his general argument. If, at some point in cultural development, human thought and morality can transcend biology, does that mean that some human beings can escape the illusion of objectivity and decide rationally what is, in fact, true and right? Could they, for example, decide whether Darwin’s theory of evolution is objectively true? Indeed, Ruse insists that we can know “beyond reasonable doubt” that Darwinian evolution is a fact (p. 4). If so, then we must wonder why he says so often that human beings can never know objective truth.
Ruse acknowledges the contradiction between metaphysical skepticism and Darwinian science. “I confess that the notion that there is not something solidly real to this world sounds somewhat ludicrous to a person whose basic thesis is that we all got here in an ongoing clash between rival organisms” (p. 187). To escape this paradox, he adopts Hume’s common-sense realism, according to which, in Hume’s words, we must affirm “that the operations of nature are independent of our thought and reasoning.”
But far from resolving the contradiction, this only restates it. Nature either does or does not exist independently of our minds. We cannot believe both propositions simultaneously. Of course we can pretend to believe in metaphysical skepticism and then act on our common-sense belief in metaphysical realism, which was Hume’s peculiar way of doing things. But then what’s the point of pretending to believe what we do not believe? It’s one of the oddest of the distinguishing features of modern thinkers beginning with Descartes: we show our profundity by feigning belief in preposterous ideas that could be seriously believed only by the insane.
Ruse speaks of himself as a philosophic “naturalist.” The more appropriate label would be “idealist” or “solipsist.” Like most professional philosophers today, he claims to believe the premise of the early modern philosophers (such as Descartes, Hobbes, Locke, and Hume) that the mind knows directly only its own states—”ideas,” “representations,” or “impressions.” Therefore, he must also pretend to believe that the order that we think we see in nature (such as causality) is in fact only the order in our minds. We mistakenly identify our subjective impressions with objective reality. It is an absurd vision, but Ruse endorses it (or, again, pretends to endorse it) in its Humean form (pp. 182-86). Ruse exposes himself to the same solipsistic idealism that plagued Hume. And like Hume he tries to cure himself by fleeing to the “world of common sense,” that strange world in which people believe they can know something about reality. At this point Ruse’s teaching becomes as incoherent as Hume’s. He cannot enter the world of common sense as a skeptical alien. He cannot live in that world while still believing it’s all an illusion.
To live in the world of common sense, to be a true “naturalist,” one must recognize the Aristotelian distinction between that which is apprehended in the mind and that by which it is apprehended. Ideas are not the objects of apprehension; rather, ideas are that by which we apprehend objects. Ideas are the conceptual vehicles by which we reflect on things in the world. This simple thought supports the realism that is commonsensical because it is metaphysical.
One cannot be a metaphysical skeptic and a common-sense realist at the same time, for once one has affirmed metaphysical skepticism, one cannot speak about the natural reality of either the mind or morality. Hume’s skepticism requires him to say that a mind is nothing but “a heap of impressions.” Yet how could a heap of impressions have all the capacities and needs that Hume attributes to the mind? Why should these impressions be heaped in one way rather than another? When Hume speaks of the natural passions of the mind, he has to speak of it as Aristotle would-a substance with natural attributes-in contradiction to metaphysical skepticism.
Similarly, in his account of morality, Hume has to assume a universal human nature. At the beginning of An Enquiry Concerning the Principles of Morals, he contends that moral distinctions depend upon “some internal sense or feeling, which nature has made universal in the whole species.” Here he cannot speak of human beings as random heap of impressions. Rather, he must speak of them as members of a natural species endowed with natural inclinations, which is to speak the language of Aristotelian (and common-sense) realism. After all, a consistent adherence to Humean skepticism would make it impossible to say anything about human nature. Humean beings would not be human beings at all.
Ruse is wrong, therefore, in linking Darwinian biology and Hume’s philosophy. The Darwinian biologist must believe that human beings have a genetically distinct nature. To assume that they are only accidental heaps of impressions would be the most radical rejection of biological science. The problem is not peculiar to Hume’s thinking. Metaphysical skepticism in any form must deny that there is any natural order to things, which denies the possibility not only of biology but of any science.
Metaphysical skepticism would also deny the reality of human nature as the foundation of morality. Insofar as morality is a biological adaptation, Ruse believes, we must regard it not as “something objective, in the sense of having an authority and existence of its own, independent of human beings,” but rather as “subjective, being a function of human nature, and reducing ultimately to feelings and sentiments” (p. 252). Ruse is using the concept of subjectivity in a special sense. In speaking of the subjectivity of morality as being a part of human nature, he wants to take a middle way between “traditional objectivism” and “traditional subjectivism” (pp. 215-17). Morality has no objective reference to any reality that would be eternal and independent of human beings (such as God’s law or Plato’s ideas). But neither is morality subjective in the sense of being merely a matter of personal choice or arbitrary feelings. Morality rests on a sense of obligation binding on all human beings. “Killing Jews because they are Jews is absolutely, objectively wrong. Period” (p. 215).
Humans share a common moral understanding. This universality is guaranteed by the shared genetic background of every member of Homo sapiens. The differences between us are far outweighed by the similarities. We (virtually) all have hands, eyes, ears, noses, and the same ultimate awareness. That is part of being human. There is, therefore, absolutely nothing arbitrary about morality, considered from the human perspective. I, like you, have forty-six chromosomes. I, like you, have a shared moral sense. People who do not have forty-six chromosomes are considered abnormal, and (probably) sick. People who do not have our moral sense are considered abnormal, and (probably) sick (p.255).
It would seem that Ruse would agree with Abraham Lincoln’s argument that slavery is absolutely wrong and contrary to our natural moral sense, because it means that some human beings are treated as if they were not human. Our shared humanity as members of the same species is an objective fact that cannot be denied without absurdity.
Why then doesn’t Ruse regard this grounding of morality in a universal human nature as sufficient to secure the objectivity of morality? His reasoning is that although human nature is not just a matter of personal whim, neither is it eternally fixed. Human beings arose from an evolutionary process in the past and could be altered in the future either by natural selection or by genetic engineering. Consequently, human nature is contingent. Although slavery contradicts human nature as we now know it, Ruse might say, we could have evolved so that, like some species of ants, some of us would have been genetically designed for slavery. And in the future, we might be able through biotechnology to alter our nature to produce a caste society based on genetic differences. Aldous Huxley foresaw this in his Brave New World.
We might now have visions of Nietzschean projects for genetic manipulation in the service of a transvaluation of all values. But Ruse hesitates. “Morality is a part of nature, and . . . an effective adaptation. Why should we forego morality any more than we should put out our eyes?” (p. 253). To which the Nietzschean nihilist might respond, If our eyes deceive us, why not put them out? Ruse has no good answer as long as he accepts Hume’s metaphysical skepticism, which denies the very possibility of seeing anything as it truly is.
If Ruse were to embrace common-sense realism as metaphysical realism, we would have an answer for the nihilist. That we have eyes might be an accident of evolution. And someday there might be a universe without us or any other sighted beings to look upon it. But for now we have eyes, and even if now we see as through a glass darkly, we see something of what the world is like. Our sight may have originated as a tool for survival and reproduction, yet now it is more than that. To see is to understand, and to understand is for us desirable for its own sake. To see is not only to live but to live well, to live in a manner proper to our nature. To see whatever there is to see is to be fully awake and thus fully alive. And everywhere we look we see intelligible order. We all understand Darwin’s amazement when he looked at the adaptation of parts in an orchid and declared: “I never saw anything so beautiful.”
Since we live in and through our bodies, our sight as well as all of our vital capacities will decay and die. That is the way with all things that depend on body. But doesn’t our looking with comprehension and wonder upon the world, our looking for the enduring patterns in all things, intimate some participation, even if momentary, in the eternal order? How else could we explain the intellectual passion of Darwin in his quest to look upon the principle governing all life-orchids as well as barnacles, frogs as well as men?
Ruse would say that although Darwin’s brain was designed by natural selection only to promote his biological fitness, he was able to use it for scientific understanding as well. “We get the tools through organic evolution,” Ruse explains. But “what we produce has a meaning of its own, transcending biology, as we push our tools of understanding to produce ever better pictures of the world” (p. 206). Does this imply that the mind (as the capacity for thought) is not simply identical to the brain (as the organic product of evolution)? Is the brain the necessary but not sufficient condition for the mind? Dare we suggest that to speak of human thought as “transcending biology” reminds some of us of the old-fashioned idea that human beings have souls?
In any case, it would be disastrous for the defenders of Darwin to accept Ruse’s Humean interpretation of Darwinian biology. The popularity of Creation science depends not on the specious arguments for its scientific validity, but on the belief that Darwinism promotes a nihilistic assault on reason and morality. Ruse confirms that belief by insisting that to become a Darwinian one must deny that one can ever know objectively what is true or right. To put science in opposition to common sense provokes a natural (and sensible) animosity among common people, who lack the talent of clever people for believing nonsensical ideas. And insofar as science itself is ultimately a refinement of common sense, a scientific denial of common experience would be intellectual suicide. We cannot take Darwin seriously if we have no reason to take anything seriously.