Leibniz paused. “Soul is a word frequently mentioned in connexion with monadology. It is a word of diverse meanings, most of them ancient, and much chewed over by theologians. In the mouths of preachers it has come in for more abuse than any other word I can think of. And so perhaps it is not the wisest choice of term in the new discipline of monadology. But we are stuck with it.”
“Are they like human souls?”
“Not at all. Allow me, your highness, to attempt to explain how this troublesome word soul became entangled in this discourse. When a philosopher braves the labyrinth, and sets about dividing and subdividing the universe into smaller and smaller units, he knows that at some point he must stop, and say, ‘Henceforth I’ll subdivide no further, for I have at last arrived at the smallest, elemental, indivisible unit: the fundamental building-block of all Creation.’ And then he can no longer dodge and evade, but must finally stick his neck out, as it were, and make an assertion as to what that building-block is like: what its qualities are, and how it interacts with all the others. Now, nothing is more obvious to me than that the interactions among these building-blocks are stupefyingly numerous, complicated, fluid, and subtle; just look about yourself for irrefutable proof, and try to think what can explain spiders, moons, and eyeballs. In such a vast web of dependencies, what laws are to govern the manner in which one particular monad responds to all of the other monads in the universe? And I do mean all; for the monads that make up you and me, your highness, feel the gravity of the Sun, of Jupiter, of Titan, and of the distant stars, which means that they are sensitive of, and responsive to, each and every one of the myriad monads that make up those immense bodies. How can they keep track of it all, and decide what to do? I submit that any theory based on the assumption that Titan spews out atoms that hurtle across space and whack into my atoms is very dubious. What is clear is that my monads, in some sense, perceive Titan, Jupiter, the Sun, Dr. Waterhouse, the horses drawing us to Berlin, yonder stable, and everything else.”
“What do you mean, ‘perceive’? Do monads have eyes?”
“It must be quite a bit simpler. It is a logical necessity. A monad in my fingernail feels the gravity of Titan, does it not?”
“I believe that is what the law of Universal Gravitation dictates.”
“I deem that to be perception. Monads perceive. But monads act as well. If we could transport ourselves much closer to Saturn, and get into the sphere of influence of its moon Titan, my fingernail, along with the rest of me, would fall into it-which is a sort of collective action that my monads take in response to their perception of Titan. So, your highness: What do we know of monads thus far?”
“Infinitely small.”
“One mark.”
“All the universe explainable in terms of their interactions.”
“Two marks.”
“They perceive all the other monads in the universe.”
“Three. And-?”
“And they act.”
“They act, based on what?”
“Based on what they perceive, Dr. Leibniz.”
“Four marks! A perfect score. Now, what must be true about monads, to make all of these things possible?”
“Somehow all of these perceptions are flooding into the monad, and then it sort of decides what action to take.”
“That follows unavoidably from all that has gone before, doesn’t it? And so, summing up, it would appear that monads perceive, think, and act. And this is where the idea comes from, that a monad is a little soul. For perception, cogitation, and action are soul-like, as opposed to billiard-ball-like, attributes. Does this mean that monads have souls in the same way that you and I do? I doubt it.”
“Then what sorts of souls do they have, Doctor?”
“Well, let us answer that by taking an inventory of what we know they do. They perceive all the other monads, then think, so that they may act. The thinking is an internal process of each monad-it is not supplied from an outside brain. So the monad must have its own brain. By this I do not mean a great spongy mass of tissue, like your highness’s brain, but rather some faculty that can alter its internal state depending on the state of the rest of the universe-which the monad has somehow perceived, and stored internally.”
“But would not the state of the universe fill an infinite number of books!? How can each monad store so much knowledge?”
“It does because it has to,” said the Doctor. “Don’t think of books. Think of a mirrored ball, which holds a complete image of the universe, yet is very simple. The ‘brain’ of the monad, then, is a mechanism whereby some rule of action is carried out, based upon the stored state of the rest of the universe. Very crudely, you might think of it as like one of those books that gamblers are forever poring over: let us say, ‘Monsieur Belfort’s Infallible System for Winning at Basset.’ The book, when all the verbiage is stripped away, consists essentially of a rule-a complicated one-that dictates how a player should act, given a particular arrangement of cards and wagers on the basset-table. A player who goes by such a book is not really thinking, in the higher sense; rather, she perceives the state of the game-the cards and the wagers-and stores that information in her mind, and then applies Monsieur Belfort’s rule to that information. The result of applying the rule is an action-the placing of a wager, say-that alters the state of the game. Meanwhile the other players around the table are doing likewise-though some may have read different books and may apply different rules. The game is, au fond, not really that complicated, and neither is Monsieur Belfort’s Infallible System; yet when these simple rules are set to working around a basset-table, the results are vastly more complex and unpredictable than one would ever expect. From which I venture to say that monads and their internal rules need not be all that complicated in order to produce the stupendous variety, and the diverse mysteries and wonders of Creation, that we see all about us.”
“Is Dr. Waterhouse going to study monads in Massachusetts, then?” Caroline asked.
“Allow me to frame an analogy, once more, to Alchemy,” Daniel said. “Newton wishes to know more of atoms, for it is through atoms that he’d explain Gravity, Free Will, and everything else. If you visited his laboratory, and watched him at his labours, would you see atoms?”
“I think not! They are too small,” Caroline laughed.
“Just so. You instead would see him melting things in crucibles or dissolving them in acids. What do such activities have to do with atoms? The answer is that Newton, unable to see atoms with even the finest microscope, has said, ‘If my notion of atoms is correct, then such-and-such ought to happen when I drop a pinch of this into a beaker of that.’ He gives it a go and sees neither success nor failure but some other thing he did not anticipate; then he goes off and broods over it, and re-jiggers his notions of atoms, and devises a new experimentum crucis, and re-iterates. Likewise, if your highness were to visit Massachusetts and see me at work in my Institute, you’d not see any monads lying about on counter-tops. Rather you would see me toiling over machines that are to thinking what beakers, retorts, et cetera, are to atoms: Machines that, like monads, apply simple rules to information that is supplied to them from without.”
“How will you know that these machines are working as they ought to? A clock may be compared to the wheeling of the heavens to judge whether it is working aright. But what is the action that your machine will take, after it has applied the rule, and made up its mind? And how will you know whether it is correct?”
“That is easier than you might suppose. For as Dr. Leibniz has pointed out, the rules need not be complicated. The Doctor has written out a system for conducting logical operations through manipulation of symbols, according to certain rules; think of it as being to propositions what algebra is to numbers.”