Tertium non data

"The alchemists have a saying, "Tertium non data': the third is not given. That is, the transformation from one element to another, from waste matters into best gold, is a process that cannot be documented. It is fully mysterious. No one really knows what effects the change. And so it is with the mind that moves from its prison to a vast plain without any movement at all. We can only guess what happened"

- From Fortunata's Story, Sexing the Cherry by Jeanette Winterson