Last weekend we watch G. Paltrow and J. Gyllenhaal being lovestruck tormented mathematicians in the film version of David Auburn’s Proof. Their characters commiserate and argue and have sex and agonize grandly over mathematical proofs. In an indirect way it keeps making me think of a brilliant scene at the beginning of Tom Stoppard’s Arcadia, when precocious teenager Thomasina and her witty twentysomething tutor Septimus, circa 1809, talk of Fermat and the facts of life:

THOMASINA    Septimus, what is carnal embrace?

SEPTIMUS   Carnal embrace is the practice of throwing one’s arms around a side of beef.

THOMASINA   Is that all?

SEPTIMUS   No … a shoulder of mutton, a haunch of venison well hugged, an embrace of grouse … caro, carnis; feminine; flesh.

[...]

SEPTIMUS   I thought you were finding a proof for Fermat’s last theorem.

THOMASINA   It is very difficult, Septimus. You will have to show me how.

SEPTIMUS   If I knew how, there would be no need to ask you. Fermat’s last theorem has kept people busy for a hundred and fifty years, and I hoped it would keep you busy long enough for me to read Mr Chater’s poem in praise of love with only the distraction of its own absurdities.

[...]

THOMASINA   I think you have not been candid with me, Septimus. A gazebo is not, after all, a meat larder.

SEPTIMUS   I never said my definition was complete.

THOMASINA   Is carnal embrace kissing?

SEPTIMUS   Yes.

THOMASINA   And throwing one’s arms around Mrs Chater?

SEPTIMUS   Yes. Now, Fermat’s last theorem —

THOMASINA   I thought as much. I hope you are ashamed.

SEPTIMUS   I, my lady?

THOMASINA   If you do not teach me the true meaning of things, who will?

SEPTIMUS   Ah. Yes, I am ashamed. Carnal embrace is sexual congress, which is the insertion of the male genital organ into the female genital organ for purposes of procreation and pleasure. Fermat’s last theorem, by contrast, asserts that when x, y and z are whole numbers each raised to power of n, the sum of the first two can never equal the third when n is greater than 2.

(Pause.)

THOMASINA   Eurghhh!

SEPTIMUS   Nevertheless, that is the theorem.

THOMASINA   It is disgusting and incomprehensible. Now when I am grown to practise it myself I shall never do so without thinking of you.

SEPTIMUS   Thank you very much, my lady. Was Mrs Chater down this morning?

THOMASINA    No. Tell me more about sexual congress.

SEPTIMUS   There is nothing more to be said about sexual congress.

THOMASINA    Is it the same as love?

SEPTIMUS   Oh no, it is much nicer than that.