30 Phil, Chapter 15, Saint Augustine, Touchstone 38: Chronoception.

According to Einstein’s theory of relativity, time is intertwined with space in a four-dimensional continuum known as spacetime. However, our experiencing of it is called chronoception. Augustine was one of the first to describe time as a subjective experience. Today we know it is influenced by a variety of factors, including our attention, memory, and emotions, as well as things like light and noise. Time is commonly perceived as something external, an attribute of reality. Augustine brought an introspective approach asserting the “sense” of time is within us.