What do you do when you see a picture of a toddler with his hands tied and his throat cut? A week ago on Saturday I was scrolling through the #Syria hashtag on my Twitter feed when pictures of the Houla massacre started coming through. That night I looked at many of them. I shook, sobbed but I kept looking.
I’ve seen worse in the days since then: video footage not of dead children but of dying ones. A young boy, his throat slashed, appears to be dead but suddenly gasps for breath. Someone gently, so gently, undresses him. Another gasp, Then silence. A chubby baby in a nappy, bleeding from stab wounds, screams in agony. The screaming goes on and on. A tiny newborn lies still in its blanket, then gulps for air. Is still again, for a long time. Another gulp. But weaker now.
There is enormous controversy about whether the media should publish this kind of material. In this country, they don't; last week’s Times front page  showing a close up of dead boy was exceptional in every sense, but it did not show the physical destruction of a child’s body wreaked by shells, bullets and knives. That was left to Martin Fletcher’s extraordinary accompanying words - and to read his simple description of the children’s corpses was to shudder and despair.
But nothing he or I write conveys the violation of a child’s body slashed and stabbed and smashed that an image can sear into your understanding of what one human being can do to another. Pictures and footage of Houla's dead and dying children - and the many others killed before them - can be seen on YouTube and via Twitter, and I think people should sometimes choose to look.
I look out of respect, because that child felt terror and pain; for me, to look at that image - or watch footage of their terrible dying - is to begin the process of attempting to acknowledge what they went through, to fully know that until minutes before they had been laughing and squabbling and refusing to eat their tea just as my children do, and to value the incalculably precious life that has been stolen from them.
The media in some countries runs this kind of material as standard, and it leads to charges that people become inured to the horror of violent death. I’m sure that’s the case. The impact of the Times’s front page derives from the rarity of using such an image so prominently. I imagine the team which put that page together agonised about whether to go with that picture, or to use of the more graphic ones, or indeed to show an image of a dead child at all.
In this country, we don’t face the prospect of being killed in our own homes and streets. We rarely confront the prospect or consequence of violent death. Our unfamiliarity is a privilege - seeing it occasionally, though it’s nothing like living it, makes others’ pain harder to ignore.
My pain on looking is, by comparison, of no relevance - except, importantly, in terms of what such feelings might galvanise me to do. Looking - and choosing to keep looking - at this kind of image must prompt action, else it becomes not only emotionally devastating but ultimately pornographic and disrespectful.
I've not known what to do for months now, but last Saturday night, I knew I had to do something or I would always be ashamed.
On Sunday 10 June, at noon till 2pm, the 'Stop Killing Children' protest will be held outside the Syrian embassy, 8 Belgrave Square, London. Please join us. Bring your kids. It's not enough. I don't know what is. But doing something must be better than doing nothing. And without me seeing those pictures, this wouldn’t be happening.
Follow protest updates on #stopkillingSyrianchildren and on the Facebook Event page  (which includes some of the type of imagery described in this column)