Fluxions

A play

Giacomo Casanova & Isaac Newton & William Stanley Jevons

A table with three chairs and a stack of cards

A room. A table. On the table, a stack of cards. The three men seated around the table.

JEVONS

(turning the first card)

Bodies.

NEWTON

Bodies attract one another according to their mass and their distance.

CASANOVA

In my experience, sir, bodies attract one another according to entirely different considerations.

NEWTON

Such as?

CASANOVA

Pleasure.

JEVONS

I have been working on pleasure as well, and I have proposed that it can be analyzed using your kind of apparatus, Sir Isaac.

NEWTON

I am glad to hear it. I trust you will cite me — and not that German fellow.

CASANOVA

An apparatus for pleasure? That sounds promising. Does it bind the hands, or does it simply encourage cooperation?

NEWTON

I was referring to calculus.

CASANOVA

Ah! The calculus of seduction — yes, I have practiced that for many years.

NEWTON

And what are its variables?

CASANOVA

Eyes, for a beginning.
Then timing.
Then courage.

NEWTON

(turning to Jevons)

What is he talking about?

JEVONS

I venture to say he is talking about the fair sex.

CASANOVA

Indeed I am. Pray, tell me more about this delightful apparatus you have designed.

NEWTON

The apparatus consists in the method of fluxions, by which quantities that vary may be expressed and their rates of change determined.

JEVONS

A most formidable idea, Sir Isaac. For my own part, I propose that pleasures vary in degree, and that their increments may be examined by the same mathematical apparatus you devised. Thus the apparently capricious motions of human conduct may perhaps be reduced to mathematical analysis.

CASANOVA

Reduced? But, my dear sir, if pleasure could ever be reduced, Venice would long ago have become a very quiet city.

NEWTON

Even Venice must obey the laws of nature, and these laws imply that one day the sea will reclaim it.

CASANOVA

Then let us enjoy her while she still floats.

JEVONS

Gentlemen, perhaps it is time for another card.

JEVONS

(turning the next card)

Value.

CASANOVA

Value? Is this a question of virtue, or of gold?

JEVONS

Neither. Value arises from utility — from the degree of pleasure a thing affords when weighed against another.

NEWTON

Value may also arise from transmutation.

CASANOVA

Transmutation?

NEWTON

Lead into gold.

JEVONS

If I may say so, Sir Isaac, posterity has tended to admire your other investigations more.

NEWTON

Has gold, then, ceased to be valuable?

CASANOVA

Mr. Jevons, do tell me this is not true.

JEVONS

(ever so slightly blushing)

No, sir, I can relieve you of that worry. It merely turns out that, ahem…

NEWTON

That what?

JEVONS

(bracing himself)

That lead cannot be so easily transmuted, I am afraid to say.

NEWTON

I never presumed it would be easy.

JEVONS

(hesitating)

It would seem, Sir Isaac, to be impossible.

CASANOVA

Then I shall be delighted to hear that only gold remains gold. Time for another card?

NEWTON

(taking a deep breath)

Perhaps this is the best way forward under the circumstances.

JEVONS

(turning the next card)

Chance.

CASANOVA

Ah, chance — the most faithful accomplice of pleasure.

NEWTON

There is no such thing as chance. What men call chance is merely their ignorance of the causes that govern events.

JEVONS

Perhaps so, Sir Isaac. Yet even where the causes remain obscure, man must still choose. And I have learned that some successors of mine have devised another kind of apparatus that can deal with that.

CASANOVA

An apparatus for chance? That sounds like a gaming table.

JEVONS

Quite so. Games are precisely what the successors of mine have used as their model.

CASANOVA

Games are about taking risks — much like seduction, where the risks are considerable but the rewards of pleasure loom invitingly.

NEWTON

As do the rewards of alchemy.