This reminds me of a story
What is air

When you debate with the know-all ask them that simplest of things: “what is this (which you believe to know so well)? What is it?” Most people are unable to answer properly. Socrates used this question to prove the arrogant that they don’t know what they speak about. This reminds me of a story:
Tamerlane was a savage beast in his soul but he was a clever man too and liked to surround himself with studious and God-fearing people. Among the erudite and the believers the Emir felt as if he himself were enlightened and good. In this company of respectable ulemas and muftis Nasreddin was just a pet, kept to amuse the moments of boredom. Unfortunately, while Timur was amused, Hoça rarely pleased the scholars and they did their best to get rid of the Sufi jester who mocked so often the folly of the learned. At one time of danger they went to denounce him at the feet of Timur and requested – in the name of right thinking and religion – the Hodja to be beheaded for heresy.
Nasreddin was brought in the presence of Timur who said,
“Worm, this appears to be your end. The clear thinking sages in my divan found your opinion and your words wrong. You confuse the believers with perplexing teaching and mistaken notions. Can you defend yourself?”
“Great Master, replied Nasreddin, before having me put to death, please try these philosophers, so excellent in learning, perfect lawyers, careful inquirers, precise and subtle debaters, with one simple question, to see if their thinking is clear indeed. Pray, ask them to answer – one by one – a simple question: What is air?”
Timur, who liked to try out people as he liked to play chess, ordered the ulemas to write down, each separately, the meaning of air. In no time they came back with their answers.
“It’s emptiness, mere nothing.”
“It is the breath of Allah!”
“Air is the principle of life, the pure food of the lungs.”
“Air is the godly substance connecting all essences while allowing us to move freely trough it”
“It is the quiet mother of tempest.”
“The stuff lying promises are made of.”
“Who could know what air is? It comes and goes invisible, without trace.”
“It is the simplest and cheapest element, aplenty for the rich as for the poor.”
It was precisely what Nasreddin had expected."
“Master of the lucky constellations, do you see how these people cannot agree on the simplest thing? Would you entrust people who falter in understanding the air they breathe to judge on your behalf matters of right and wrong or life and death?”
Timur agreed.