If you are trying to explain a mystery, you can give a name to what the explanation might be so you can talk about it; but beware of being certain that it actually exists.
Epicycles, crystal spheres, ‘absolute’ time and space,
Impetus, dark matter (holding galaxies in their place),
Dark energy, phlogiston and fundamental particles* –
All these have been proposed as hypothetical articles.
Such words have been invented, throughout mankind’s short history,
By philosophers and scientists when they confront a mystery.
But giving names to mysteries can make them seem so real:
It’s never long before they gain great popular appeal.
The older ones have been replaced (by orbits, relativity,
Oxygen, momentum) with increased objectivity.
But some remain, so when you hear them bandied all about,
Do bear in mind they’re models, and maintain a sceptic’s doubt.