I finally got round to watching the last episode of the fifth series of House Of Cards, which puts me behind the game compared with those who watch it on Netflix and ahead of it compared with those waiting for the box set, though for that to count as an advantage I’d need to have understood who’s done what to whom, and I don’t. So there’s no need to fear a spoiler. You can’t spoil a plot you don’t understand.

As a rule of thumb, I’d say that when a thing feels overcomplicated to me it’s either because it’s been going on too long, or I have. We’re not alone. Extrusion is the besetting sin of our times. Nothing knows its limits. Make one successful programme and before you know it they’re calling it a series. Pick up a dozen viewers and they’re offering you a second series. You’re free to say no if you want to. But who can say no to a second series? To a programme-maker, a second series is like the promise of eternal life.

So you construct your first series in such a way as to make viewers want a second series, too. You make promises you can’t keep, leave conclusions unconcluded, the dead half-living, the living half-dead, threads dangling from the tapestry for the next set of weavers to pick up and leave dangling in their turn.

Call this artifice, but don’t call it art. Art generates its own imperatives. There’s no pulling Anna Karenina out from under the wheels of the train to bump up the viewing figures; and it won’t make us feel a jot less cheated if the series continues under the title Call Count Vronsky.

I won’t pretend I don’t look forward to seeing more of something I’ve enjoyed. I’d have watched The Sopranos for ever. But you can feel opposing things simultaneously: want more and want less. There was a time when critics demanded that the wicked be punished and the virtuous rewarded. I wouldn’t dare turn the television off in my house because I felt the virtuous weren’t getting their rewards. As for the wicked going unpunished, well, we keep our fingers crossed. But the greatest stories have a dramatic, if not moral logic, more persuasive than their own perpetuation. Don Giovanni goes to hell. The end should mean the end.

People asked Rembrandt how he knew when his work was finished. “When I say it is,” was his answer. It’s a question of aesthetic integrity and there’s no measuring that. Wagner’s Ring goes on too long for me for me to sit through, though I love the music. But I fancy that, had he been offered a second series, he’d have declined on the grounds that it was finished.