“Leibniz imagined the mind as a large machine, a processing unit, a factory, a mechanism — which seems fair enough. Leibniz imagined walking around a large mill. You would see cogs and levers moving, but, as David Eagleman says: "It would be preposterous to suggest that the mill is thinking or feeling or perceiving. How could a mill fall in love or enjoy a sunset? A mill is just made of pieces and parts. And so it is with the brain, Leibniz asserted. If you could expand the brain to the size of a mill and stroll around inside it, you would only see pieces and parts. When we look inside the brain, we see neurons, synapses, chemical transmitters, electrical activity. We see billions of active, chattering cells. Where are you? Where are your thoughts? Your emotions? To Leibniz, the mind seemed inexplicable by mechanical causes.”