“When one rows, it is not the rowing that moves the ship; rather rowing is simply a magical ceremony by which one compels a demon to move it.” Nietzsche, F. (1996), Human, All Too Human, Cambridge University Press.

This is without doubt my favourite piece of vicious Nietzschean rhetoric. It’s guaranteed to get up the nose of every self-respecting professor of Physics. I always quote it in my lectures on Science’s First Mistake, the book I wrote with my old pal Dionysios Demetis.

I usually pull it out of my hat during the Q&A, when some pompous questioner always insists that the world is linear, objective and ‘obeys the Laws of Science’. My response is to ask if the questioner is an empiricist, namely basing his (it’s usually a he) analysis on scientific observation and measurement. When they answer in the affirmative, I ask them to show me gravity.

Invariably they drop something, to which I respond: “That’s not gravity. You’ve just dropped something. Show me the gravity that did that. Come on, you claim to be an empiricist, show me the evidence of it’s existence.” In other words show me the gravity demon!!!

I end with “Newton’s apples fall, not because of gravity, but because that’s what apples do. This gravity you talk about isn’t in the world, it’s all in your head and the way you describe things that are necessarily so.” This is the also case for every ‘force’ in Physics. Each is a demon, which can only ever appear as a proxy in the world of measurement. They are very useful demons, but they are demons none the less.