'Then you must agree that in the modern world, mathematicks is at the heart of Natural Philosophy – it is like the mysterious essence in the core of the snowflake. When I was fifteen years old, Mr. Waterhouse, I was wandering in the Rosenthal – which is a garden on the edge of Leipzig – when I decided that in order to be a Natural Philosopher I would have to put aside the old doctrine of substantial forms and instead rely upon Mechanism to explain the world. This led me inevitably to mathematicks.'