How We Learn Right from Wrong — Letters from a Stoic

How do we first learn what is good and what is honourable? Letter 120 takes up the epistemological question underneath all of Seneca's ethics: where does our knowledge of virtue actually come from? Nature could not teach us this directly, he says, she gave us the capacity but not the content.

What we learned, we learned from observation: we noticed the differences between men, studied the faces of the wise, and gradually abstracted from those examples the concept of the perfectly good. The concept of the ideal man came from real men, the way we form the concept of a number too large to count from numbers we have actually counted. The letter then moves into one of its most memorable passages, the instruction to maintain your character consistently from the beginning of life's drama to the end.

Most of us shift our masks. At times thrifty and serious, at times wasteful and idle. We play a part contrary to the one we discarded, so that the man seen yesterday is unrecognizable today.

The test of character is not its quality at any single moment but its consistency across a life. Men should be able to praise you, or at least identify you.