“Now that must’ve improved the King’s mood to no end!”

“We can only speculate. He has gotten worse. The sorts of Doctors who prescribe powders and elixirs have, consequently, fallen from favor, and the bleeders and purgers are upon us!”

“Then I’ll add my weight as President, to yours as Secretary, of the Royal Society, and we’ll see how long we can keep the lancets in their sheathes.”

“Interesting point you raise there, Roger…”

“Oh, Daniel, you have got that Waterhousian brooding look about you now, and so I fear you do not mean a literal point, as in lancets- ”

“I was thinking-”

“Help!” Roger cried, waving his arms. But the watermen on yonder dock had all turned their backs on the Privy Stairs to watch the approach of the boat carrying those chirurgeons.

“D’you recall when Enoch Root made phosphorus from horse urine? And the Earl of Upnor made a fool of himself supposing that it must have come from royal piss?”

“I’m terrified that you’re about to say something banal, Daniel, about how the King’s blood, bile, et cetera are no different from yours. So is it all right with you if I just stipulate that Republicanism makes perfect sense, seems to work well in Holland, and thereby exempt myself from this part of the conversation?”

“That is not precisely where I was going,” Daniel demurred. “I was thinking about how easily your cousin was replaced with Anglesey-how disappointingly little difference it made.”

“Before you corner yourself, Daniel, and force me to drag you out as usual, I would discourage any further usage of this similitude.”

“Which similitude?”

“You are about to say that Charles is like Comstock and James is like Anglesey and that it will make no difference, in the end, which one is king. Which would be a dangerous thing for you to say-because the House where Comstock and Anglesey lived has been razed and paved over. ” Roger jerked his head upwards towards Whitehall. “Which is not a fate we would wish on yonder house.”

“But that is not what I was saying!”

“What were you saying, then? Something not obvious?”

“As Anglesey replaced Comstock, and Sterling replaced Raleigh, I replaced Bolstrood, in a way…”

“Yes, Dr. Waterhouse, we live in an orderly society and men replace each other.”

“ Sometimes.But some can’t be replaced.”

“I don’t know that I agree.”

“Suppose that, God forbid, Newton died. Who would replace him?”

“Hooke, or maybe Leibniz.”

“But Hooke and Leibniz are different. I put it to you that some men really have unique qualities and cannot be replaced.”

“Newtons come along so rarely. He is an exception to any rule you might care to name-really a very cheap rhetorical tactic on your part, Daniel. Have you considered running for Parliament?”

“Then I should have used a different example, for the point I’m wanting to make is that all round us, in markets and smithys, in Parliament, in the City, in churches and coal-mines, there are persons whose departure really would change things.”

“Why? What makes these persons different?”

“It is a very profound question. Recently Leibniz has been refining his system of metaphysics-”

“Wake me up when you are finished.”

“When I first saw him at Lion Quay these many years ago, he was showing off his knowledge of London, though he’d never been here before. He’d been studying views of the city drawn by diverse artists from differing points of view. He went off on a rant about how the city itself has one form but it is perceived in different ways by each person in it, depending on their unique situation.”

“Every sophomore thinks this.”

“That was more than a dozen years ago. In his latest letter to me he seems to be leaning towards the view that the city does not have one absolute form at all…”

“Obvious nonsense.”

“… that the city is, in some sense, the result of the sum total of the perceptions of it by all of its constituents.”

“I knew we never should have let him into the Royal Society!”

“I am not explaining it very well,” Daniel admitted, “because I do not quite understand it, yet.”

“Then why are you belaboring me with it now of all times?”

“The salient point has to do with perceptions, and how different parts of the world-different souls-perceive all of the other parts-the other souls. Some souls have perceptions that are confused and indistinct, as if they are peering through poorly ground lenses. Whereas others are like Hooke peering through his Microscope or Newton through his Reflecting Telescope. They have superior perceptions.”

“Because they have better opticks!”

“No, even without lenses and parabolic mirrors, Newton and Hooke see things that you and I don’t. Leibniz is proposing a strange inversion of what we normally mean when we describe a man as distinguished, or unique. Normally when we say these things, we mean that the man himself stands out from a crowd in some way. But Leibniz is saying that such a man’s uniqueness is rooted in his ability to perceive the rest of the universe with unusual clarity-to distinguish one thing from another more effectively than ordinary souls.”

Roger sighed. “All I know is that Dr. Leibniz has been saying some very rude things about Descartes lately-”

“Yes, in his Brevis Demonstratio Erroris Memorabilis Cartesii et Aliorum Circa Legem Naturalem- ”

“And the French are up in arms.”

“You said, Roger, that you would add your weight as President, to mine as Secretary, of the Royal Society.”

“And I shall.”

“But you flatter me by saying so. Some men are interchangeable, yes. Those two chirurgeons could be replaced with any other two, and the King would still die this evening. But could I-could anyone- fill your shoes so easily, Roger?”

“Why, Daniel, I do believe this is the first time in your life you’ve actually exhibited something akin to respect for me!”

“You are a man of parts, Roger.”

“I am touched and of course I agree with the point you were trying to make-whatever the hell it might have been.”

“Good-I am pleased to hear you agree with me in believing that James is no replacement for Charles.”

Before Roger could recover-but after he mastered his anger-the boat was in earshot and the conversation, therefore, over.

“Long live the King, m’Lord, and Doctor Waterhouse,” said one Dr. Hammond, clambering over the boat’s gunwale onto the Privy Stairs. Then they all had to say it.

Hammond was followed by Dr. Griffin, who also greeted them with “Long live the King!” which meant that they all had to say it again.

Daniel must have said it with a noticeable lack of enthusiasm, for Dr. Hammond gave him a sharp look-then turned toward Dr. Griffin as if trolling for eyewitnesses. “It is very good that you have come in time, m’Lord,” said Hammond to Roger Comstock, “as, between Jesuits on the one hand, and Puritans on t’other” (squirting long jets of glowing vitriol out of the pupils of his eyes, here, at Daniel), “some would say the King has had enough of bad advice.”

Now Roger tended to say things after long pauses. When he’d been a clownish sizar at Trinity, this had made him seem not very intelligent; but now that he was a Marquis, and President of the Royal Society, it made him seem exceedingly sober and grave. So after they’d all climbed up the steps to the balcony that led into the part of Whitehall called the King’s Apartments, he said: “A King’s mind should never want for the counsel of learned or pious men, just as his body should never want for a bountiful supply of the diverse humours that sustain life and health.”