The first few times I read Monadology, I gave up when he insisted the monads had perception. Sorry Leibniz, even after you divide perception from conscious perception, insisting on any perception in a plant or a molecule or a star is the point where I get off the bus. But in revising the text again I was suddenly struck by the sheer genius and insight of the argument. Here’s the shortest tour of the logic:
1.) A monad is a simple substance, and ever since Aristotle we’ve agreed that substances are what remain unchanged throughout activity, growth, or the stages of life or existence.
2.) If the monad stays the same throughout activity, growth, or stages of existence (e.g. a man thinking, a plant growing, a star running the course from nebula to black hole or supernova) then it is like a text we read out loud or a program that is being run. When we read a text out loud, the text stays the same (thank goodness – imagine if the words shifted around on us) but its manifestation in the world – the words of the narrative – changes. So too the program and the video game that is being run off of it.
3.) But in order to transition from a text to its narration or from a program to the video game is a transition that happens either mechanically or perceptually. But it can’t happen mechanically, because then the code itself would have to push or pull or move, but this is exactly what it doesn’t do. The change happens through a reader. Absent this reader, there is no mediation of the monad and its changing projection into the world.
4.) Even where readers are mechanical, they do not read as mechanical but so far as they respond to what something means. Whatever mechanical changes are brought about by a string of binary digits hotting a laser is of no value apart from a decision to have them mean something, and reading only occurs as a result of this decision. A mechanical process can mediate the decision to have a string mean something and the output of the string, but the mechanical process itself is no more reading than a pair of tongs is alive when it is used by the hand.
5.) But if the monad is reading, it’s perceiving, even if this occurs non-consciously, like the way we perceive where the floor is when we’re walking or how to reposition our body when we pick up something heavy.
If this is right, Leibniz is intuiting the monad as an information system or sort of code that plays itself out in stages. The penetration of insight is astonishing.