Sometimes, I need to write about something but just don’t know how to start. Whatever it is that has incited the need to write is either too wonderful, too weird or too terrible to introduce ‘naturally’. It would either sound glib, blasé, cold, mundane… or just awkward. Today the cause is definitely in the ‘terrible’ category and the tone is all of those I mention plus more.

So maybe back a bit, to what I’d wanted to write when I got up this morning. I’ve been getting increasingly edgy about the whole EU referendum polling and trying to keep myself calm by saying “pre-election poll bump” under my breath all week. I am very firmly in – and disappointed by the case-making skills of – the remain camp. Leaving will be a disaster. There’s nothing tangible to be gained, the entire case for exit seems to be based mostly on lies and I’m feeling increasingly ashamed to be British. And even, more broadly considering what’s going on in the US, the Middle East and the rest of the world, to be human.

I was going to set out some arguments for why I feel so strongly this way. I’m a pragmatist when it comes to politics, so it’s not out of ideological fervour that I want to stay in. It’s that, based on the facts, I literally can’t see why anyone would think leaving the EU would be a good idea. It isn’t. It’s a terrible idea and I can’t help but conclude that people are voting based on feelings, not careful consideration or facts.

And then I saw the news breaking this afternoon, about the crushingly sad murder of Jo Cox. Then, with a level of predictability that was almost equally depressing, I saw it immediately being politicised. Not by the campaigns. Not directly. But by the people on each side of the debate, the ones who care, the ones who will vote. A woman – a good, charitable one, by all accounts – died horrifically in unconfirmed circumstances. A representative of our democracy. Someone whose job was quite literally to represent us. All of us. Not just those who voted for her, but everyone. And the first thing many people sought to do was use it to win an argument.

Now don’t get me wrong, it’s an important argument. One the victim herself considered important, too. Her attacker may or may not have felt strongly about it as well. Early reports suggest he may have, but it’s too early to tell and, to be honest, irrelevant. If it is linked to the referendum, this attack could have happened to someone on either campaign. It’s not about one side being nice and the other nasty. One being wrong and the other being right. There are some pretty hateful idiots on both sides. There are also many caring, earnest, well-meaning people on both sides. It isn’t about the sides, it’s about the way cases have been made, the standards we’ve (not) held ourselves to in promoting and criticising them.

But this reaction, this instinct to immediately point the finger at a single cause of something… that is I think, ironically, the primary cause of such tragic, senseless anger. Our entire political atmosphere has become poisoned by fear and hate. Partisanship and raw, unfettered ideology have dragged us free from facts, made us worry more how we feel than how we think – in contrast to what we think – and drowned out the quiet tug of conscience and respect for each other.

It doesn’t matter if you think X or Y about a matter, only how you reach that conclusion and then conduct yourself in advocating it. You are indeed free to speak your mind, but you are also responsible for your words. I don’t mean “he told me to do it” or “it hurt my feelings”, but that if you use your freedom to preach fear and hate of the other then you must understand that has an impact on the world. How we behave – including what we say and how we choose to say it – is an act of practical democracy, a will towards the world being a bit more that way.

If you are kind, that is a vote for a kinder world. If you are cruel, for a crueller one. And if you spread hate and fear, you are making the world a bit more fearful and hateful. When you attach that, parasite-style, to a popular issue, it can have a huge impact. Not only does it generally make the world a worse place, but it also risks triggering those who are vulnerable and unstable into doing something far more awful than your ‘mere words’ may have ever been meant to.

Now it hasn’t in any way been confirmed that Jo Cox’s killer had documented mental health issues, nor what motivation there was for his attack. However, I would suggest that anyone who carries out such an act must have had persistent or latent mental health problems. If we keep the tone respectful and the debate factual, such instabilities are left largely unaffected. We minimise the risk of them exploding into sudden, awful activity. But instead we pour fuel on the fire and fan the flames, which exacerbates those issues and has all-too devastating results.

It is not just here, of course. The rise of Trump, the Orlando attacks, Islamic State, Irish sectarian violence… it all rides on a tide of the same mentality, the herding instinct of the human animal. Western society, neo-liberalism, modern democracy; call it what you will, but it has been slowly poisoned by our failure to take responsibility in this way. We’ve been so negligent of how we conduct ourselves, both in public and within our own heads, that we’ve driven ourselves back to the problems we thought we’d overcome. In freely, incrementally, lazily allowing our behaviour and our rhetoric to mirror that of The Bad Old Days, when fascism rose and nearly destroyed us, we’ve returned to exactly what brought it about in the first place; fear and division. Blame and hate.

We’ve mistaken passionate advocacy for fear-mongering and bullying. An environment of hyper-ideological rhetoric and divisive finger-pointing has been explained away as healthy debate and freedom of expression. Removed from humility and respect for both facts and those with whom we differ, the only way to feel we’re progressing the discourse is to constantly up the ante. Shout louder. Be more extreme. Rely on shock factor rather than nuance. Those who argue with conviction are held as highly or more so than those who argue with consideration and caution.

But feeling strongly about something is no more licence to ignore contrary evidence or just plain respect and decency than it is to murder someone in the street. The responsibility for Jo Cox’s death is of course firmly at the feet of her killer, just as the actions of Islamic State are at theirs. But the responsibility for the environment that shapes the minds behind those actions is one we all carry.

At the very base of all things, we are accountable to one another because we are responsible for one another. This is our world and our actions shape it. Looking at the current state of things, we’ve taken particularly poor care of ourselves, as individuals and as a whole. No vote or ideology matters at all against the one metric that counts; what kind of people we make ourselves, what world we build in doing so and the care we take in both.

RIP Jo Cox. I’m sorry our collective failure cost you and your family so dearly.