"After we visited Wilkins on his death-bed," said Leibniz, "we went to a coffee-house, did we not, and talked. We spoke of Mr. Hooke’s observations of snowflakes—their remarkable property, which is that each of the six arms grows outwards from a common center, and each grows independently, of its own internal rules. One arm cannot affect the others. And yet the arms are all alike. To me this is an embodiment of the pre-established harmony. Now, Daniel, in like manner, there grows out of the core of Natural Philosophy more than one system for understanding the Universe. They grow according to their own internal principles, and one does not affect another—as Newton and I demonstrated yesterday by utterly failing to agree on anything! But if it’s true—as I believe—that they are rooted in a common seed, then in the fullness of time they must adopt a like form, and become reflections of one another, as a snowflake’s arms."