Classic texts—those that are widely considered as being part of a “canon”—have countless insights into well-being that are still relevant today. But as education focuses more on identity politics than on imparting knowledge, this material is being taught less and less. It doesn’t help that most classics have a socially conservative ethos, that almost all were written by men and that many of the most influential texts in the U.S. come from the Western tradition. Now many educators are scrubbing these books from curricula. As a result, many of the teachings that were well-known in previous generations are gradually being forgotten.

These texts aren’t just beautiful and historically important. They are useful. Some concepts from this literature have even been used to develop psychotherapies, such as Plato’s model of the psyche or the writings of the Stoics. But, as helpful as these therapies can be, it would probably be better if the concepts on which they’re based were still taught in schools and maintained in the broader culture.

Obviously, it’s impossible to summarize all the wisdom of the classics, but a few principles keep recurring. They’re found in both Western and Eastern classics, and many are supported by current peer-reviewed psychological literature. They’re core principles for health, fulfillment and well-being that seem to transcend culture and time. And by reading the texts that expound these principles, we’ll be equipped with tools that can help us lead happier, less stressful lives.