Conclusion

Link to Danish translation by Sandra Knudson

For an essay on developments in psychology from 1967 (when I took introductory psychology) to 2017 (when I taught my last intro course and retired from the University of California, Berkeley), see "50 Years of Psychology: A Personal Look Back at "Intro". For a broader perspective, see Humans: Why We're Unlike Any Other Species on the Planet, a special issue of Scientific American (09/2018) on "The Science of Being Human".

On the Temple of Apollo, at the foot of Mount Parnassus, near Delphi in Greece, there is a single inscription that sums up the Western tradition:

gnothi sauton, or "Know thyself".

(There was also another injunction:meden agan, or "Nothing in excess".)

Socrates (470-399 BCE) was condemned to death (by drinking hemlock) for corrupting the youth of Athens. According to Plato (Apology), Socrates held that

"The unexamined life is not worth living".

These two aphorisms exemplify the "Golden Age" of Greek philosophy, and the beginnings of the Western tradition.

In the 17th century, the French philosopher Rene Descartes (1596-1650) rejected everything he had been taught by authority in church and school, and resolved to achieve human knowledge by the application of human reason alone. He began by doubting everything except that truth could be known through reason -- everything, including the fact of his own existence. He resolved his stance of radical doubt when he concluded that from his conscious experience of thinking that he must exist:

"I think, therefore I am".

By defining himself as "a thing that thinks", Descartes initiated the modern tradition of philosophy out of which psychology evolved.

Psychology is a full participant in this tradition of Western thought, attempting to answer through the scientific method questions that have been posed by philosophers for more than 2,500 years:

Writing toward the end of the 18^th century, Immanuel Kant argued that psychology could never be a science, because science was based on measurement and the mind, being immaterial, could not be measured. Nevertheless, less than half a century later, Ernst Weber and Gustav Fechner asked their subjects to assign numbers to the intensity of their sensory experiences, and discovered the first psychophysical laws. Shortly thereafter, Hermann von Helmholtz began his experiments on the perception of distance and depth, and Franciscus Donders showed how reaction times could measure the speed of mental processes. In 1879, Wilhelm Wundt established the first psychological laboratory at the University of Leipzig, and in 1890 -- only a century after Kant's pronouncement -- William James produced the first comprehensive textbook summarizing the principles of the new "science of mental life".

Wundt believed that scientific psychology was limited to the study of immediate experience, and that the "higher" mental processes, such as memory and thought, were not susceptible to experimental investigation. Nevertheless, in the 1880s Hermann Ebbinghaus measured the strength of a memory by how long it took him to memorize a list of nonsense syllables, doing for memory what the psychophysicists had done for the "lower" mental process of sensation and perception. Francis Galton introduced standardized tests of individual differences in mental functions -- a paradigm quickly adapted, along with Donders' reaction-time method, by Emil Kraepelin for the experimental study of mental illness. At the end of the century, Ivan Pavlov and Edward Thorndike began their studies of learning in animals, and Norman Triplett conducted the first experimental study of social influence.

These gains were consolidated in the early years of the 20^th century.

By 1931, when Muzafer Sherif experimentally studied the effect of social conformity on the perception of motion, the circle was complete and psychology emerged full-fledged as a quantitative, experimental science of individual mental life in its biological and social context.

What Psychology Tells Us About Ourselves

Psychology has made marked progress since then, expanding its understanding of cognitive, emotional, and motivational processes, their relations with behavior, their biological substrates, and their ties to the social and cultural context in which the individual lives.

In the short lifespan of psychology as a science, we have learned a number of important things about how mental life, and in some cases -- visual perception, memory, and categorization come to mind -- we have a fairly complete understanding of how our minds work. And we have also learned a number of important things about ourselves.

The first and most important theme in psychology is that mind matters. Human behavior is intelligent: it goes beyond reflexes, taxes, instincts, and conditioned responses. We do not simply respond automatically to environmental events. Rather, we behave in accordance with our internal,mental representations of these events. Our actions are based on our perceptions of the present, our memories of the past, and our expectations for the future. For this reason, cognitive functions, having to do with the acquisition and use of knowledge, constitute the primary subject matter for psychology:

Of course, cognition is not all that the mind does, and so psychology is also concerned with non-cognitive functions:

As Kant noted, there are three irreducible faculties of mind -- knowledge, feeling, and desire. Psychology must understand all of them.

The second, equally important, theme is interaction -- the mutual influence among causal elements as they combine to produce an outcome. Interactions occur:

Because of this interactional theme, psychology must be an extremely broad science, connecting many different levels of analysis.

One particularly interesting set of interactions are those between nature and nurture:

The human mind, with its capacity for intelligence, language, and consciousness,is what the brain does, and the human brain is the most important legacy of biological evolution -- more important than walking upright, more important than having fingers rather than toes.

The third lesson is that We create the environment through thought and action.

Our capacity for intelligence, consciousness, and especially language sharply divides the dullest human from the smartest chimpanzee, and gives us a uniquely human ability not just to adapt to our environments, but to adapt our environments to us. It is worth noting that the human brain, which the evolutionary psychologists tell us was specifically geared to h. sapiens living naked in the East African savannah of the late Pleistocene era, permitted us to move out of the Environment of Early Adaptation, invent clothes, control fire, and populate the entire surface of the Earth -- including permanent settlements in Antarctica, and maybe someday the Moon and Mars. All without a scintilla of biological difference between our brains and those of Adam and Eve.

There is something of a paradox here, which is that the distinctly human capacity for intelligence, consciousness, and language, which is a product of biological evolution, creates the possibility of culture -- which in turn gives us the means to transcend the very biological forces which allowed it to come about. Unlike other animals, we do not have to rely on learning by trial and error; we can make use of social learning, including sponsored learning, deliberate teaching, in institutions like universities. .Unlike other animals, we do not have to rely on accidents of natural selection, but can literally make ourselves and the world around us.

Such transcendence has its limits, of course: We're all going to die. But within broad limits, it is a fundamental fact of human nature that we deliberately shape the world to fit us. We do not have to rely on accidents of natural selection, or even accidents of learning, to shape us to fit the world.

In a very real sense, the human mind is the basis of human freedom because it gives us three unique abilities:

By using our minds, we can change ourselves and the world around us, and promote our advancement into a higher, better, form of life.

But we can do this only if we take Socrates seriously, and attempt to understand ourselves -- not just our place in the universe, but also how our minds work and how we behave. That is the larger task of psychology: to understand the nature of human experience, thought, and action, and the role that the human mind plays in human life.

This page last revised 05/08/2019.