A theme that comes up often in commentaries about contemporary American culture is the absence of firmly grounded and widely embraced basic values among the people. While Americans have a coherent and stable enough legal tradition, they seem to lack a basic ethics by which their lives might be guided or given meaning. It is for this reason, it is often said, that people require religion in their lives.

Why do we need values? Because humans lack instincts. We are born with the instinct to suckle, and that is about it — the rest is a matter of learning. Each of us must learn on our own to figure out ideas, to form principles about life and its innumerable facets. America is a highly pluralistic country — millions of people live here, coming from extremely diverse cultures, traditions, religions and ethnic groups. It seems, therefore, that just relying on such backgrounds as sources of the common bond of ethics will not help. Instead, as elsewhere in the world, such sources often pit people against one another. Christians versus Jews or Muslims, Muslims against ‘infidels,’ agnostics against theists, atheists against agnostics, and so on — there is no end of the varieties of conflict that can arise if we depend on these sources for moral guidance. Why? Because they lack a common base. They draw their principles of human behavior from diverse belief systems that are, themselves, not grounded in some common and accessible reality.

When we depend on the teachings of our culture, we can be reasonably sure that some connection to reality must have infused what we believe. However, a good deal of it is myth and fiction, made up by the human imagination and showing about as much diversity as that faculty can produce.

So what can Americans hope for? There is, first of all, no guarantee that we will come together on any possible answer as we search for a common ethics. That is because human beings are quite free to ignore even the best answers to questions they pose — say, if they find an answer to be unpleasant, disturbing, scary, inconvenient or whatnot. But some answers probably offer a better chance at consensus than others.

In ancient Greece, it was Socrates — the first major Western philosopher — who proposed an answer to this question of how to come by an ethics that we can all agree on, even if we do not choose to. He proposed that reason must be used to study human nature and that when we learn what human nature is, we will also learn how to live right. Human nature is something we can all study. It is there before us every second of every minute of every hour of our lives. We have ample opportunity to examine what it is to be a human being. And doing so will give us a strong clue as to how to live a human life properly, ethically.

The most important thing about human beings is that they are living creatures who must use their minds to navigate their lives. It is human intelligence, the activity of figuring things out and living accordingly that seems to be the best guide to living well.

As Socrates put it, “The unexamined life is not worth living.”

But only nature and, for our purposes, human nature, is available for common study and ultimate consensus.

In a diverse society such as America, the people cannot hope to reach peace, harmony and justice by finding principles from diverse traditions. Trying to do so runs the serious risk of conflict, since people interact so frequently and pervasively. What we need to learn is to use, trust and be guided by the one thing all humans have in common — our reasoning capacity.

Using reason to study our world may get us what all else has failed to, namely, a set of ethical guidelines that will help us come to agree on solutions to our problems.

There is no utopia in trusting reason. But as novelist Scott Turow put it in his bestselling book “The Burden of Proof:” “In human affairs, reason would never fully triumph; but there was no better cause to champion.”

Tabor Machan is RC Hoiles Professor of business ethics and free enterprise at the Argyros School of Business and Economics, Chapman University, and a research fellow at the Hoover Institution, Stanford University.