Seven Theories of Human Nature is a general introduction to philosophical anthropology. Written by Leslie Stevenson, who was a Reader in Logic and Metaphysics at the University of St. Andrews, this book focuses not only on major theories of what it is to be a human being but it also makes suggestions for how to evaluate competing theories.
In discussing how to evaluate competing theories Stevenson notes that a theory of human nature can be maintained in the face of intellectual difficulties in two ways: “(1)not allowing any conceivable evidence to count against the theory, and (2) disposing of criticism by analyzing the motivations of the critic in terms of the theory itself.” (15) If the theory is defended in this way then the theory is a “closed system.” If a theory of human nature necessarily leads to a “closed system,” and it explains away all evidence against the theory, then, we must wonder whether such a system is genuinely justifiable. Stevenson prefers a scientific approach to the examination of these theories. These theories, he says are hypotheses, which can never be known for certain, but can be put to the test by observation and experiment. If these theories make correct predictions then the theory can be justifiably held, if however, the theories’ predictions get falsified then they cannot be rationally held. With this approach to evaluating theories in hand, Stevenson proceeds to examine seven different theories of human nature, those of Plato, Christianity, Marx, Freud, Sartre, Skinner, and Lorenz.
The majority of the chapters follow a similar pattern: there is a presentation of the context of the view, a “diagnosis,” followed by a “prescription,” and then a critical discussion of the view. When he treats Plato for example, he says that the diagnosis that Platonism offers is that most individuals do not manifest the harmony of the three parts of the soul. This defect leads to defective human societies. The prescription for this problem is to help people is to have philosopher kings who can help mold society towards justice (of the society and also of the soul). He then levels standard critiques against Platonism, like the mysterious nature of the Forms, its overly rationalistic understanding of action, and the danger of having philosopher-kings.
There are certainly some theories within this book that are treated more charitably than others. Christianity and Marxism are analyzed in a critical but appreciative manner. Freudian Pyschoanalysis and Skinner’s Behaviorism are heavily critiqued. Yet at the end Stevenson seems to favor the theory of Konrad Lorenz, who was one of the founding fathers of “ethology,” the scientific study of animal behavior. Upon reading this chapter I noted that Lorenz was simply engaged in evolutionary psychology. This was an insightful chapter for me since, I have to admit, I was not familiar with Lorenz prior to reading this book. According to Lorenz, the “diagnosis” is that the human species is threatened with extinction. The prescription is innate aggression. This aggression keeps us alive, yet at the same time if pushed to far it might cause destruction not only of individuals but of the entire species.
What ties all these theories together is that they all offer some account of innate tendencies which are a problem, as well as a proposed solution. Other themes that emerge in the book are the relationship between the material and non-material parts of humans, freedom vs. determinism, rationality vs. desire. Overall this book provides a helpful overview of major theories of human natur