However, it’s a question that Civilisations (BBC2, Thursdays, 9pm) tackles head on, and it seems the answer is art.
It’s difficult to argue with presenter Simon Schama, as right from the outset he relates the demise of Khaled Al-Asaad, the head of antiquities in the ancient Syrian city of Palmyra.
When ISIS invaded the city, he refused to tell them where the city’s art treasures were hidden, so the fanatics beheaded him.
And there, in a nutshell, was this first programme’s argument – art equals civilisation, the rejection of art equals barbarism.
Schama took us on an illuminating jaunt around the world, looking at ancient art, from neolithic cave paintings to the carved stone edifices of the Maya, in central America.
There was tiny, delicate bone carving of a head, which Schama argued was “the dawn of the idea of beauty”.
The crowning glory, however, was the amazing carvings from the Mycenaean empire of ancient Greece, incredibly intricate battle scenes etched in beautiful detail.
The photography was beautiful, and Schama’s commentary was eloquent and lyrical.
But what really stood out, and it was something that Schama alluded to, was how art stood as an expression of power, wealth and technological advancement.
Once early civilisations had shelter, warmth and food, they inevitably turned to art, as if to say look, we’re so advanced we can spend our energy and time on these magnificent frivolities – on carving, and painting and architecture – we are civilised, you are not.
So, Masterchef’s back (BBC1, times vary), the moveable feast of the BBC’s schedule, but I fear Gregg Wallace has become such a self-parody of the chirpy Cockney geezer that he’s virtually unwatchable.
Homeland (Channel 4, Sundays, 9pm) is back, upping the paranoia for poor beleagured Carrie. However, even with Trump in the White House, the top-level shenanigans stretch credulity.