Pure linearity would be just one darned thing after another; and nothing could be learned from it because the past is no guide to the future.
Pure circularity would be mere repetition, with no possibility of breaking out, we would be bound by fate - and nothing could be learned from it.
The first condition of pure linearity is modernity - indistinguishable from the incomprehensibility of chaos; the second condition of pure cyclical history is the hunter gatherer (or Hindu) world view, with a constant state of reality (now and always, past and future) varied only by the temporary swirlings of energy and recyclings of form.
Christian history is a a linear, purposive, and end-stopped sequence of multiple repeated themes or leitmotiven - recognizable recurrences, but inexact recurrences.
We may perceive pattern, in large and in small, but the outcome is not fated: there are at least two outcoes to each story - one positive, one negative (e.g the outcome of repentance, or of pride), and at the crux of each recurrent theme is a choice.
Wisdom is in applying the correct story to the current situation; recognizing the choice, then making the right choice.