Heraclitus was a philosopher in Ephesus around 500 BC, a man so reliably cranky that his contemporaries called him the Obscure and later the Weeping Philosopher. He wrote a single book, which has survived only as fragments quoted by later authors. Fragment 60 is one line long. The way up and the way down are one and the same. Nothing else in the fragment. Classic Heraclitus.

The line resists the modern tendency to split everything into progress or decline. Heraclitus is pointing at the fact that the staircase is the staircase. The same steps carry you in both directions. Whether a given motion counts as ascent or descent is a question of where you started and where you claim to be going, both of which are narratives laid on top of the physical fact. The stairs are neutral. The meaning is authored.

A Siamese coming three-quarters down a staircase at twilight is neither arriving nor leaving, which is the cat's default position on most things. The human watching it is already narrating: where is it going, what does it want, why now. The cat, magnificently, does not care. The stairs are the stairs. Up and down are a grammar we imposed on a surface that only cares about being crossed. Heraclitus, sulking in Ephesus, would have respected the cat's disinterest.