I'm not a 'causes' sort of girl. Not a gung-ho sort of ho. I'm just not cut out for campaigning; it makes me think limply of laminators and litter-picks. Occasionally my social conscience will stir, like a sleepy kitten glutted with the cream of consumer content that suddenly recalls the thrill of the hunt, and I'll pounce on the nearest Amnesty petition in a flurry of flying fur.

But then I get distracted by happy, shiny things, and guiltily add another tributary to my trickle of charity direct debits.

Moreover, when I do get worked up about something, it's embarrassingly random, indicating a flimsy moral compass and an energetic ability to bandwagon-jump. This weekend I got rather het up about the conservation of native butterflies because I read some feature in the Telegraph. Tomorrow, because I've just taken delivery of The Reluctant Escapologist, the memoir from The Bush Theatre's inspiring and beardy ex-Artistic Director Mike Bradwell, I'll no doubt be eulogising the rape of the fringe.

But two similar arts-related causes have recently lodged in my mind with uncharacteristic stickiness. One is the BFI's campaign to restore nine early silent Hitchcock films that may otherwise crumble away. If I know one thing, it's that we don't need less stuff like this in the world.

The other is the National Portrait Gallery's appeal to acquire William Hoare's portrait of Ayuba Suleiman Diallo (1733), Britain's earliest known portrait of a black African Muslim and a freed slave. Sure, the guy was actually an unscrupulous slave-trader himself back on the banks of the Gambia, but as the ever-righteous Bonnie Greer puts it:

"The most moving thing of all, more important than even the story of this heroic and influential man, is that Ayuba Sulieman Diallo's face is the face of contemporary Britain,.Go out into our major cities and you will see him all around you - male and female. His face speaks to today, speaks to those who feel disconnected from the story of this great land. He speaks, too, to those who want to distort this story, ruin it, make it a lie. Therefore this portrait is at once an important historical artefact and a major contemporary work. It breathes. The portrait of Ayuba Sulieman Diallo is a national treasure and must be saved for the nation."

The last sentence makes my toes curl, but still, the woman has a damn good point. Go and look at it. It's special.

So: help. That's my best shot. I'm not sending you a bloody adoption pack.

Oh God, I know it should be Afghanistan, and Haiti, and donkey sanctuaries. But a misogynistic film director and a three hundred year old slave trader are, at least, a start.