Aristotle’s Metaphysics boldly begins: “All human beings by nature desire to know.” There is in us, Aristotle suggests, an inherent urge or inclination to find an explanation or account of things. And we seek knowledge about many things: today’s weather, the stock market, whether a divine being exists. But among all the different forms knowledge can take, one stands out as especially fundamental: self-knowledge. We want to understand who we are. There is something about the ancient injunction, inscribed into the Temple of Apollo at Delphi, to “know thyself” that strikes us as profound — a worthy and admirable object of pursuit. Rousseau wrote:
Of all human sciences the most useful and most imperfect appears to me to be that of mankind: and I will venture to say, the single inscription on the Temple of Delphi contained a precept more difficult and more important than is to be found in all the huge volumes that moralists have ever written.
Not only is knowledge of ourselves rewarding for its own sake, it is significant also for understanding ethics and politics. Without knowing basic facts about how we are disposed to feel, think, and act, it seems almost impossible to figure out how we should live or the political structures that are best suited for generating goodwill, cooperation, and peace. For these reasons, philosophers have long sought to deepen our understanding of the drives and inclinations that move human beings toward various ends, and the characteristics that mark us out as the kind of beings we are — in short, what constitutes “human nature.”
In this sense of “nature,” human beings would be only one instance of a very large class of nature-possessing entities, a class that one might argue includes every type of living thing. After all (and oversimplifying a bit), cacti store water, spiders spin webs, elephants move in groups, and each of these activities seems to be connected with the distinct nature of each kind of organism. And while we can also talk about the nature of water, chairs, or triangles, some philosophers have argued that there is a special sense of “nature” that properly applies only to living entities: cacti, spiders, and elephants possess natures because they are organic, animate things that are marked by particular forms of life. Even to understand an individual entity as a cactus, spider, or elephant, we draw upon an interpretive background of the characteristic features and patterns of behavior that structure their lives as creatures of a particular kind. This interpretive background helps us to make sense of different bits of behavior. For instance, why is that plant storing water like that? Because it’s a cactus, and cacti tend to live in deserts where water is scarce. Or, why does that animal create webs like that? Because it’s a spider and that’s how this kind of spider traps its prey. In this way, applying the concept of nature helps us to identify and classify organisms, providing structure and intelligibility to the natural phenomena that constitute the realm of the living.
But while this sense of “nature” seems useful in general, it is also difficult to clarify in its specifics, especially when applied to human beings in all their diversity. Nevertheless, the idea of human nature can be helpful for understanding both the biological and the ethical dimensions of human life.
Two Concepts of Human Nature
It may be surprising to some that the very existence of human nature has increasingly been called into question by both scientists and philosophers. Perhaps the most common objection to the existence of human nature builds on evolutionary facts that demonstrate the mutability of species. On this view, because there are no fixed sets of traits that determine each species, the classical picture must be wrong: No species has an “essence” that determines a set of necessary and sufficient conditions for species membership. As the biologist Michael Ghiselin succinctly puts it: “What does evolution teach us about human nature? It tells us that human nature is a superstition.”
But whether there is such a thing as human nature depends on what we mean by that term. The difficulty is that there appears to be more than one concept that scholars refer to by the name “human nature.” Here I will identify and clarify one of these concepts that I think is both coherent and also significant for our understanding of ethics. I call it the developmental concept of human nature.
To clarify this concept, it will be helpful first to distinguish it from a more widely employed notion of human nature, which I call the statistical concept of human nature. The philosopher of science Edouard Machery characterizes the statistical concept of human nature as “the set of properties that humans tend to possess as a result of the evolution of their species.”
The first point to note about the statistical concept of human nature is that it does not contain any essentialist elements that biologists tend to find problematic. That is, it understands human nature to be constituted not by anything immutably fixed, but by those properties that are statistically common among human beings and derive from evolutionary processes. As Machery points out, his is a purely descriptive notion of human nature based on statistical normalcy. It is not a morally significant standard that can be employed to make judgments about the sorts of characteristics that are good or bad or that human beings ought or ought not to possess. This concept does not help us identify which traits are morally good, since the traits that are statistically common are frequently connected to increasing fitness and reproduction, which may or may not be morally good or admirable.
Of course, understanding human nature in this statistical sense might still be important for ethics for other, instrumental, reasons. For instance, if there are ethical ends we ought to pursue, it will be good to know whether or how we can obtain those ends, given our physiological and psychological constitution. Just as a carpenter needs to know the physical properties of the wood that he is carving up to shape it into his desired end, the moral philosopher needs to know the characteristic features of human beings to understand how human beings can become morally good. But again, just as a hunk of wood does not determine the kind of shape it ought to take, our biological nature also does not determine the kind of ethical goals we ought to pursue. Human nature in the statistical, biological sense is likely to be a constellation of instincts, powers, and drives — a mixed bag of the good, the bad, and the ugly.
By contrast, the developmental concept of human nature that I’d like to defend can play a much more normatively significant role in ethics. It finds its roots in Aristotle (although we can find similar ideas in the thoughts of the ancient Chinese philosopher Mencius as well). Human nature, in this developmental sense, consists in those capacities, inclinations, and dispositions that arise in the normal course of human life in a nurturing environment.
Unlike the statistical concept of human nature, this is not a normatively neutral notion, as made obvious by the terms “normal” and “nurturing.” These terms point toward certain standards, which, if not met, would constitute some kind of defect or malfunction. Of course, what constitutes a normal course of human life and a nurturing environment should be subjected to much careful debate and discussion, and cannot be settled easily. Some will find such terms morally problematic and will seek to reject the notion altogether, a point that finds many worthy defenders in the growing philosophical literature on disability.
But while we need to be very careful about understanding what constitutes a normal course of human life and a nurturing environment, there are good reasons for thinking that we cannot completely abandon such concepts. Take, for example, the Zika virus outbreak in 2015–16. The widespread fear of Zika had less to do with the effects of the virus on adults (who often show no symptoms at all) than with its potential to cause “severe fetal brain defects,” as the U.S. Centers for Disease Control and Prevention puts it. But what constitutes a brain defect? Unless we can appeal to some idea of what normal human brain development is, it is difficult to know what sense can be given to such a term. Without the concepts of “defect” and of “normal” development, all we could say about the Zika virus is that it has the potential to put the fetal brain on one path of change rather than another, without being able to say anything about whether those changes are harmful or good.
That there are clear cases of what constitutes a nurturing environment for human beings can be illustrated by reflecting on the way that emotionally or physically abusive parents cause significant short-term and long-term harm to children. As John Bowlby’s attachment theory shows, children need at least one caretaker to offer emotional support to establish a “secure base” from which they can learn to navigate the world and develop healthy relationships. Without such a supportive social environment, children are much more likely to develop anxiety disorders or depression, which can further impede proper emotional, social, and physical development. This is why social environments that tend to produce such effects are considered bad or defective.
In order to make sense of proper fetal brain development and how disease, malnutrition, or physical and emotional abuse can impede human development, we must appeal to some understanding of the patterns and cycles of growth and maturation that constitute the basic form of human life.
But here is where the developmental concept of human nature becomes complicated: human beings are not only biological but also cultural beings, and how we develop and mature from infancy onward can take a variety of forms. In fact, the deepening appreciation of cultural diversity due to globalization is often cited as a reason for rejecting a universal human nature.
However, positing the existence of human nature should not deter us from fully embracing the deep influence that culture, learning, and environment have on us. The concepts of human nature and of cultural diversity are not mutually exclusive. In fact, there is increasing recognition among biologists and philosophers of biology that the whole nature–nurture debate arises from a false dichotomy, since even nature (for instance gene expression) requires the right sort of nurture or environmental conditions in order to unfold properly. A child raised by wolves would not acquire human language, even though our capacity and instinct for language is widely regarded as innate. And it would be foolish (at best) to claim that most of the cultural variations we observe in clothing, language, or food can be objectively evaluated, even though they can all be traced ultimately back to basic biological needs. To discount either nature or nurture would be akin, as Mary Midgley put it, to claiming that “the quality of food is determined either by what it is like when you buy it or by how you cook it, but not both.”
What the developmental concept of human nature offers is a way of understanding and organizing human patterns of thoughts, attitudes, and behaviors. It helps us to make sense of why human beings build shelter, store food, dance, make jokes, and raise children. But appeals to human nature do not — and simply cannot — purport to offer a full explanation of everything that human beings do. Again, culture, education, and our capacity to reflect and reason (an important aspect of human nature!) allow us to direct and redirect ourselves in a marvelously diverse range of ways. How should we go about satisfying the basic needs we have, or extend and develop our fundamental inclinations? These are open-ended questions. So retaining the concept of human nature does not narrowly confine us to a specific set of ends and rigidly fix the kinds of lives that are worthwhile or good. How each individual human being ought to carry out his life cannot be understood apart from the particular historical, social, and cultural context in which he finds himself, as well as his own set of particular desires, talents, and aspirations.
Is Human Nature a Useful Concept?
If culture ultimately plays such a crucial role, one might wonder if the concept of human nature sits a bit too idle. Perhaps it plays some role, but is not all that important for understanding human behavior or for thinking about the kinds of ends that we should set for ourselves.
This point about culture, combined with the immense variation we find among individuals in terms of habits, tastes, and personalities, seems to point toward the greater importance not of human nature but of distinct individual natures. Appealing to the natures of cacti, spiders, and elephants can go a long way toward capturing the basic patterns of movements and behaviors exhibited by these organisms. But, because individual human beings can vary so much in temperament, desires, and personalities, one might think that appealing to human nature fails to capture the distinctiveness of each person, thereby missing the mark on what really matters.
These considerations are important, and they suggest, once again, that the comprehension of human nature does not, by itself, provide a complete picture of the human world. Nevertheless, there are two important ways in which retaining the notion of human nature can be helpful.
First, appealing to human nature calls attention to the fact that we are human animals — that we are physical organisms of a certain kind that operate within the natural world. By seeing ourselves in this light, we remind ourselves that we are embodied and that there are various properties linked to this fact, such as our emotionality and physicality. We are human animals that move, feel, think, and have our being in the physical world. As such, we are continuous with the natural world and a full member of the animal kingdom.
Second, recognizing a common nature shared by all human beings provides an appealing foundation for human dignity and human rights, allowing us to make universally applicable judgments about the kinds of acts that are required or impermissible toward other human beings. This meta-ethical grounding of rights and dignity can offer a satisfying basis for a moral-political theory that is especially well suited for a globalized world. Moreover, by identifying a set of commonly shared capacities and ends, we may find it easier to humanize those that are culturally and physically different from us, by recognizing that we are united by a common set of inclinations and ends, with remarkably similar physical, emotional, and mental constitutions.
Calling attention to these deeper commonalities can engender a salutary effect on our moral thought and talk, healing divisions and directing us toward what ought to unite us in pursuing the common good.
- With the rapid development of techniques for modifying human genes, should we consider altering human nature? How should we determine whether we ought to pursue genetic modification? What are the potential benefits and harms of pursuing such technology?
- Another possible objection to the developmental concept of human nature is that, as in the biological concept of human nature, what constitutes human nature will be a mixed bag. In other words, just because a capacity or inclination arises in the normal course of human life doesn’t automatically imply that the capacity or inclination ought to be developed or exercised. How compelling is this objection?
- In both the East and the West, there has been much dispute about the goodness or badness of human nature. In the West, we find Hobbes arguing for human nature’s badness and Rousseau arguing for its goodness. In the East, two ancient Chinese philosophers, Mencius and Xunzi, also disagree about the goodness of human nature, with Mencius siding with Rousseau and Xunzi siding with Hobbes. Given our contemporary understanding of human psychology and the sciences, is there a way to settle this dispute?
- Do one’s religious values shape one’s conception of both the content and value of human nature? For example, would belief in the existence of God make it more or less likely that one would think human nature provides a foundation for morality?
The questions raised in this discussion reveal both the complexity and difficulty of the topic of human nature. As noted in the essay, not only does there appear to be more than one concept at work, but there are many challenging empirical and theoretical issues that stand in the way of making clear headway. For example, there are conceptual questions about how to distinguish nature and nurture, and whether human nature is a normative concept. There are empirical questions about how we come to possess certain human traits — are they the natural unfolding of stuff that are rooted in our genetic endowment, or are they all completely a product of learning and culture? These are important and complicated questions that were raised in both my essay and within the discussions.
In the discussion it seemed apparent that at least some were not entirely clear on the very concept of “human nature” they had in mind. I want to point this out because philosophical concepts like human nature, like the concept of “happiness,” have a role in ordinary discourse, and so can be loaded with a variety of different meanings. For this reason, it is really important to distinguish carefully the concept one has in mind by “human nature.” Without such clarifications, it will be really difficult to move the discussion forward.
But once we’ve pinned down a concept of human nature, where should we turn to for further understanding? This was an important question raised in discussion, and I suggested that the best approach will be broad, pluralistic, and interdisciplinary. Not only philosophy, but biology, cognitive science, psychology, sociology, anthropology, literature, religion, and theology can all contribute to our knowledge of human nature. While this approach is daunting, it is also the most exciting, and the only shot we have at providing a comprehensive picture of what it is to be human.