Several of the Supreme Court’s blockbuster end-of-term decisions, which cheered conservatives and horrified liberals, were largely based on “originalist” or “textualist” readings of the U.S. Constitution. In other words, the justices based their majority opinions on what they thought the Constitution meant at the time the Founders wrote it.

But there is an inherent problem with this philosophy: The Founders expected the document to grow and change over time, guided by new and better understandings of the world. Originalism makes achieving this vision far more difficult — if not impossible — in a polarized America.

In his 1932 book, “The Heavenly City of the Eighteenth-Century Philosophers,” historian Carl Lotus Becker argued that every historical era has a specific “climate of opinion” — or underlying framework that shapes how people see the world. For the Founders, it was the Age of Enlightenment (also called the Age of Reason).

Enlightenment thinkers knew that people (including themselves) were flawed, and therefore that it was absurd to think they could establish a perfect government. Yet they were also confident that rational processes could improve humanity. The logical, reasoned use of evidence in arguments and decision-making was critical. They sought to understand the absolute laws that governed both the natural world and ethical behavior within human society. Scientific, technological and social advances gave them cause for optimism.

A combination of concerted effort, study, critical examination of evidence and logical reasoning could improve humanity over time. As humanity improved itself, it would gradually and inevitably reach closer toward perfection. As Becker observed, Enlightenment thinkers “denied that miracles ever happened, but believed in the perfectibility of the human race.” Increased knowledge would necessitate human societies continually remaking their governmental structures and institutions to reach closer to perfection.

This sense of the world framed how the men who came to Philadelphia in 1787 — and their friends and colleagues who influenced their ideas — approached writing the Constitution.