"Philosophers of a Mechanick frame of mind break all things down into atoms, to which they ascribe properties that, to them, seem reasonable—which means Mechanical properties. Mass, extension, and the ability to collide with and stick to one another. Then from this they try to explain Gravity and Souls and Miracles. It leads them into difficulties. Instead, I break all things down into monads, to which I ascribe what some would call soul-like properties: they can perceive, thnk about their perceptions, decide, and act. From this it is no great difficulty to explain those things that are so troublesome, in a mechanical-minded Atomic philosophy—everything that you put under the rubric of Vegetation, including our own ability to think, decide, and act. However, it is difficult to explain the things that are, in an Atomic philosophy, idiotically simple and obvious. Such as space and time."