Quicksilver (115 page)

“Are you expecting to start one?” the sergeant answered a minute later, as if in no especial hurry to respond.

“Why do you ask me such an odd question?”

“I am trying to conjure up some understanding of how a Puritan gets himself clapped in Tower just
now,
at a time when the only friends the King
has
are Puritans.”

“You have forgotten the Catholics.”

“No, sir, the
King
has forgotten ‘em. Much has changed since you were locked up.
First
he locked up the Anglican bishops for refusing to preach toleration of Catholics and Dissenters.”

“I know that much—I was a free man at the time,” Daniel said.

“But the whole country was like to rise up in rebellion, Catholic churches were being put to the torch just for sport, and so he let ‘em go, just to quiet things down.”

“But that is very different from forgetting the Catholics, sergeant.”

“Ah but
since—
since you’ve been immured here—why, the King has begun to fall apart.”

“So far I’ve learned nothing remarkable, sergeant, other than that there is a sergeant in the King’s service who actually knows how to use the word ‘immured.’ ”

“You see, no one believes his son is really his son—that’s what has him resting so uneasy.”

“What on earth do you mean?”

“Why, the story’s gotten out that the Queen was never pregnant at all—just parading around with pillows stuffed under her dress—and that the so-called Prince is just a common babe snatched from an orphanage somewhere, and smuggled into the birth-chamber inside a warming-pan.”

Daniel contemplated this, dumbfounded. “I saw the baby emerge from the Queen’s vagina with my own eyes,” he said.

“Hold on to that memory, Professor, for it may keep you alive. No one in England thinks the child is anything but a base smuggled-in changeling. And so the King is retreating on every front now. Consequently the Anglicans no longer fear him, while the Papists cry that he has abandoned the only true faith.”

Daniel pondered. “The King wanted Cambridge to grant a degree to a Benedictine monk named Father Francis, who was viewed, around Cambridge, as a sort of stalking-horse for the Pope of Rome,” he said. “Any news of him?”

“The King tried to insinuate Jesuits and such-like
everywhere,
” said the sergeant, “but has withdrawn a good many of ‘em in the last fortnight. I’d wager Cambridge can stand down, for the King’s power is ebbing—ebbing halfway to France.”

Daniel now went silent for a while. Finally the sergeant resumed speaking, in a lower, more sociable tone: “I am not learned, but I’ve been to many plays, which is where I picked up words like ‘immured,’ and it oftimes happens—especially in your newer plays—that a player will forget his next line, and you’ll hear a spear-carrier or lutenist muttering ‘im a prompt. And in that spirit, I’ll now supply you with your next line, sir: something like ‘My word, these are disastrous tidings, my King, a true friend to all Nonconformists, is in trouble, what shall become of us, how can I be of service to his Majesty?’”

Daniel said nothing. The sergeant seemed to have become provoked, and could not now contain himself from prowling and pacing around the room, as if Daniel were a specimen about whom more could be learned by peering at it from diverse angles. “On the other hand, perhaps you are not a run-of-the-mill Nonconformist, for you are in the Tower, sir.”

“As are you, sergeant.”

“I have a key.”

“Poh! Do you have permission to leave?”

This shut him up for a while. “Our commander is John Churchill,” he said finally, trying a new tack. “The King no longer entirely trusts him.”

“I was wondering when the King would begin to doubt Churchill’s loyalty.”

“He needs us close, as we are his best men—yet not so close as the Horse Guards, hard by Whitehall Palace, within musket-shot of his apartments.”

“And so you have been moved to the Tower for safe-keeping.”

“You’ve got mail,” said the sergeant, and flung a letter onto the table in front of Daniel. It bore the address:
GRUBENDOL LONDON.

It was from Leibniz.

“It
is
for you, isn’t it? Don’t bother denying it, I can see it from the look on your face,” the sergeant continued. “We had a devil of a time working out who it was supposed to be given to.”

“It is intended for whichever officer of the Royal Society is currently charged with handling foreign correspondence,” Daniel said indignantly, “and at the moment, that is my honor.”

“You’re the one, aren’t you? You’re the one who conveyed certain letters to William of Orange.”

“There is no incentive for me to supply an answer to that question,” said Daniel after a brief interval of being too appalled to speak.

“Answer this then: do you have friends named Bob Carver and Dick Gripp?”

“Never heard of them.”

“That’s funny, for we have come upon a page of written instructions, left with the warder, saying that you’re to be allowed no visitors at all, except for Bob Carver and Dick Gripp, who may show up at the oddest hours.”

“I do not know them,” Daniel insisted, “and I beg you not to let them into this chamber under any circumstances.”

“That’s begging a lot, Professor, for the instructions are written out in my lord Jeffreys’s own hand, and signed by the same.”

“Then you must know as well as I do that Bob Carver and Dick Gripp are just murderers.”

“What I
know
is that my lord Jeffreys is Lord Chancellor, and to disobey his command is an act of rebellion.”

“Then I ask you to rebel.”

“You first,” said the sergeant.

Hanover, August 1688

Dear Daniel,

I haven’t the faintest idea where you are, so I will send this to good old GRUBENDOL and pray that it finds you in good health.

Soon I depart on a long journey to Italy, where I expect to gather evidence that will sweep away any remaining cobwebs of doubt that may cling to Sophie’s family tree. You must think me a fool to devote so much effort to genealogy, but be patient and you’ll see there are good reasons for it. I’ll pass through Vienna along the way, and, God willing, obtain an audience with the Emperor and tell him of my plans for the Universal Library (the silver-mining project in the Harz has failed—not because there was anything wrong with my inventions, but because the miners feared that they would be thrown out of work, and resisted me in every imaginable way—and so if the Library is to be funded, it will not be from silver mines, but from the coffers of some great Prince).

There is danger in any journey and so I wanted to write down some things and send them to you before leaving Hanover. These are fresh ideas—green apples that would give a stomach-ache to any erudite person who consumed them. On my journey I shall have many hours to recast them in phrasings more pious (to placate the Jesuits), pompous (to impress the scholastics), or simple (to flatter the salons), but I trust you will forgive me for writing in a way that is informal and plain-spoken. If I should meet with some misfortune
along the way, perhaps you or some future Fellow of the Royal Society may pick up the thread where I’ve dropped it.

Looking about us we can easily perceive diverse Truths, viz. that the sky is blue, the moon round, that humans walk on two legs and dogs on four, and so on. Some of those truths are brute and geometrickal in nature, there is no imaginable way to avoid them, for example that the shortest distance between any two points is a straight line. Until Descartes, everyone supposed that such truths were few in number, and that Euclid and the other ancients had found almost all of them. But when Descartes began his project, we all got into the habit of mapping things into a space that could be described by numbers. We now cross two of Descartes’ number-lines at right angles to define a coordinate plane, to which we have given the name Cartesian coordinates, and this conceit appears to be catching on, for one can hardly step into a lecture-room anywhere without seeing some professor drawing a great + on the slate. At any rate, when we all got into the habit of describing the size and position and speed of everything in the world using numbers, lines, curves, and other constructions that are familiar, to erudite men, from Euclid, I say, then it became a sort of vogue to try to explain all of the truths in the universe by geometry. I myself can remember the very moment that I was seduced by this way of thinking: I was fourteen years old, and was wandering around in the Rosenthal outside of Leipzig, ostensibly to smell the blooms but really to prosecute a sort of internal debate in my own mind, between the old ways of the Scholastics and the Mechanical Philosophy of Descartes. As you know I decided in favor of the latter! And I have not ceased to study mathematics since.

Descartes himself studied the way balls move and collide, how they gather speed as they go down ramps,
et cetera,
and tried to explain all of his data in terms of a theory that was purely geometrical in nature. The result of his lucubrations was classically French in that it did not square with reality but it was very beautiful, and logically coherent. Since then our friends Huygens and Wren have expended more toil towards the same end. But I need hardly tell you that it is Newton, far beyond all others, who has vastly expanded the realm of truths that are geometrickal in nature. I truly believe that if Euclid and Eratosthenes could be brought back to life they would prostrate themselves at his feet and (pagans that they
were) worship him as a god. For their geometry treated mostly simple abstract shapes, lines in the sand, while Newton’s lays down the laws that govern the very planets.

I have read the copy of
Principia Mathematica
that you so kindly sent me, and I know better than to imagine I will find any faults in the author’s proofs, or extend his work into any realm he has not already conquered. It has the feel of something finished and complete. It is like a dome—if it were not whole, it would not stand, and because it is whole, and does stand, there’s no point trying to add things on to it.

And yet its very completeness signals that there is more work to be done. I believe that the great edifice of the
Principia Mathematica
encloses nearly all of the geometrickal truths that can possibly be written down about the world. But every dome, be it never so large, has an inside and an outside, and while Newton’s dome encloses all of the geometrickal truths, it excludes the other kind: truths that have their sources in fitness and in final causes. When Newton encounters such a truth—such as the inverse square law of gravity—he does not even consider trying to understand it, but instead says that the world simply
is
this way, because that is how God made it. To his way of thinking, any truths of this nature lie outside the realm of Natural Philosophy and belong instead to a realm he thinks is best approached through the study of alchemy.

Let me tell you why Newton is wrong.

I have been trying to salvage something of value from Descartes’ geometrickal theory of collisions and have found it utterly devoid of worth.

Descartes holds that when two bodies collide, they should have the same quantity of motion after the collision as they had before. Why does he believe this? Because of empirical observations? No, for apparently he did not make any. Or if he did, he saw only what he wanted to see. He believes it because he has made up his mind in advance that his theory must be
geometrickal,
and geometry is an austere discipline—there are only certain quantities a geometer is allowed to measure and to write down in his equations. Chief among these is extension, a pompous term for “anything that can be measured with a ruler.” Descartes and most others allow time, too, because you can measure time with a pendulum, and you can measure the pendulum with a ruler. The distance a body travels (which can be measured
with a ruler) divided by the time it took covering it (which can be measured with a pendulum, which can be measured with a ruler) gives speed. Speed figures into Descartes’ calculation of Quantity of Motion—the more speed, the more motion.

Well enough so far, but then he got it all wrong by treating Quantity of Motion as if it were a scalar, a simple directionless number, when in fact is is a vector. But that is a minor lapse. There is plenty of room for vectors in a system with two orthogonal axes, we simply plot them as arrows on what I call the Cartesian plane, and lo, we have geometrickal constructs that obey geometrickal rules. We can add their components geometrickally, reckon their magnitudes with the Pythagorean Theorem, &c.

But there are two problems with this approach. One is relativity. Rulers move. There is no fixed frame of reference for measuring extension. A geometer on a moving canal-boat who tries to measure the speed of a flying bird will get a different number from a geometer on the shore; and a geometer riding on the bird’s back would measure no speed at all!

Secondly: the Cartesian Quantity of Motion, mass multiplied by velocity (
mv
), is not conserved by falling bodies. And yet by doing, or even imagining, a very simple experiment, you can demonstrate that mass multiplied by the
square
of velocity (
mv
²
)
is
conserved by such bodies.

This quantity
mv
²
has certain properties of interest. For one, it measures the amount of work that a moving body is capable of doing. Work is something that has an absolute meaning, it is free from the problem of relativity that I mentioned a moment ago, a problem unavoidably shared by all theories that are founded upon the use of rulers. In the expression
mv
²
the velocity is squared, which means that it has lost its direction, and no longer has a geometrickal meaning. While
mv
may be plotted on the Cartesian plane and subjected to all the tricks and techniques of Euclid,
mv
²
may not be, because in being squared the velocity
v
has lost its directionality and, if I may wax metaphysical, transcended the geometrickal plane and gone into a new realm, the realm of Algebra. This quantity
mv
²
is scrupulously conserved by Nature, and its conservation may in fact be considered a law of the universe—but it is outside Geometry, and excluded from the dome that Newton has built, it is another
contingent, non-geometrickal truth, one of many that have been discovered, or will be, by Natural Philosophers. Shall we then say, like Newton, that all such truths are made arbitrarily by God? Shall we seek such truths in the occult? For if God has laid these rules down arbitrarily, then they are occult by nature.

To me this notion is offensive; it seems to cast God in the rôle of a capricious despot who desires to hide the truth from us. In some things, such as the Pythagorean Theorem, God may not have had any choice when He created the world. In others, such as the inverse square law of gravity, He may have had choices; but in such cases, I like to believe he would have chosen wisely and according to some coherent plan that our minds—insofar as they are in God’s image—are capable of understanding.

Unlike the Alchemists, who see angels, demons, miracles, and divine essences everywhere, I recognize nothing in the world but bodies and minds. And nothing in bodies but certain observable quantities such as magnitude, figure, situation, and changes in these. Everything else is merely said, not understood; it is sounds without meaning. Nor can anything in the world be understood clearly unless it is reduced to these. Unless physical things can be explained by mechanical laws, God cannot, even if He chooses, reveal and explain nature to us.

I am likely to spend the rest of my life explaining these ideas to those who will listen, and defending them from those who won’t, and anything you hear from me henceforth should probably be viewed in that light, Daniel. If the Royal Society seems inclined to burn me in effigy, please try to explain to them that I am trying to extend the work that Newton has done, not to tear it down.

Leibniz

P.S. I know the woman Eliza (de la Zeur, now) whom you mentioned in your most recent letter. She seems to be attracted to Natural Philosophers. It is a strange trait in a woman, but who are we to complain?