The basic timeline of history, which still ornaments elementary-school classrooms, remains the way many of us picture how we got to where we are. Its ubiquity suggests that drawing history, trying to capture the shape of time graphically, on a page or in our imaginations, is fundamental to how we understand both the past and the future; we need to diagram history to grasp it, if it can be grasped at all.
There is only one history or course of time, in this view, and all humankind is swept up in it. As we tilt the right end up, we portray “the Whig interpretation of history,” a term coined in 1931 by the historian Herbert Butterfield to describe what he thought of as naïve progressive optimism, the idea that history was headed pretty directly for freedom and enlightenment. We’ve often gotten very much the same picture from progressive leaders like the Rev. Dr. Martin Luther King Jr. and former President Barack Obama, who tell the story of America as a march toward justice, characterized by the enfranchisement of oppressed groups, presented at times almost as inevitable.
On the other hand, many theorists and many traditional cultures have envisioned time as circular or at least cyclical, which is even suggested by the rhythm of day and night or of the seasons.
Nietzsche, for example, speculated that a finite number of atoms in infinite time would assume the same configurations again and again, infinitely. But many ancient philosophies, such as Stoicism, and ancient religions, such as some elements of Hinduism, believed in the wheel of time (or kalachakra). We talk this way informally as well, when we say that history repeats itself, and certainly the idea that we live in an era when fascists and capitalists are squaring off against socialists all over the world sounds like 1930, and 1890 and 1850.
The repetitions are striking but not exact, so perhaps history has a loop structure.
It's cyclical, but it often doubles back on its journey forward. Here we might also think of progress pursued through a revival of traditional values, or radical reform movements that make what almost appears to be a reactionary appeal to the source or origin, as in the philosophy of Confucius or the Reformation of Martin Luther.