Everything we think we know about the world is a model. Every word and every language is a model. All maps and statistics, books and databases, equations and computer programs are models. So are the ways I picture the world in my head—my mental models. None of these is or ever will be the real world.
Donella H. Meadows, Thinking in Systems: A Primer
“The negligible is nothing other than what has to be neglected in order to construct physics; it is not by any means what is of no importance, because what is neglected is always an infinite error. What is neglected is always as large as the world, exactly as large, because the physicist neglects the whole difference between something that happens in front of his eyes and a perfectly closed, perfectly definite system which he conceives in his mind and represents on paper by symbols and signs; and this difference is the world itself, the world which presses around every morsel of matter, and filters into it, and inserts infinite variety between two points no matter how close together, the world which makes any closed system absolutely impossible. The world is neglected because it has to be; and, since mathematics cannot be applied to phenomena at a lesser price, it is applied at the price of an infinite error.”
-Simone Weil