Our media culture values certainty, consistency and dogmatism. Television and radio debates encourage intellectual trench warfare: we're over here, you're over there. Everyone else, pick a side.

Twitter and other social media (sorry, but you knew this was coming, didn't you?) make the whole thing worse. Arguing in short bursts, without the benefit of all the non-verbal bits of conversations, is difficult enough, without the added problem that it's much easier to be an arsehole to someone when you don't have to get the same Tube home from the pub afterwards.

Under those conditions, there's a seductive appeal about hanging on to bad positions, just because they'll get you less grief, and defending stupid things you've said in the past, because to concede any weakness during an argument feels too much like giving your opponent an advantage. But that's toxic: I don't want to be forced to defend everything I said in 2003 in order to have an opinion in 2013. I was an idiot in 2003. I only hope I'm slightly less of an idiot now.

Changing your mind is not a sign of weakness. It's a sign of strength: that you have continued to test your ideas, even the ones that you held most strongly, against the evidence. Sometimes, the evidence will change. Other times, you will.

I asked our bloggers if there was any subject on which they had changed their minds since they started writing regularly. Six of them were kind enough to respond, and their responses are below, along with mine.

Eleanor Margolis

When I first came out as gay, I was a bit suspicious of bisexuals. I was 19 and I’d spent a few years identifying as bi myself, then realised I was just in denial about being a lesbian. I assumed that, because of my own experience, bisexuality was a kind of gateway drug to full blown dykedom. Either that or a fleeting deviation from heterosexuality. It didn’t help that, the year I came out, Katy Perry was singing about kissing girls and liking it. For many women, sexual experimentation was the new It Bag.

But I came to realise that applying my own reality, when it comes to sexual identity, to anybody else’s was a huge mistake. I was recently quoted in the Guardian, saying that I don’t believe in sexual fluidity. That’s not true. What I actually meant was that I resent being told that, as a woman, I am inherently sexually fluid. As a teenager, I worked hard at sexual fluidity and it was an unmitigated disaster. That’s not to say that for many people it’s an absolute fact. Strange things happen; one day I could wake up fancying men. A woman in China did sprout a horn, after all.

Frances Ryan

When I was 22 a stranger died. Daniel James was injured in a rugby training accident, became paralysed from the chest down in 2007, and a year later flew to a Swiss euthanasia clinic to end his life.

I remember the strange feeling of anger at the time – at him perhaps, and the many who read Daniel's desire “not to live a second class existence” and glossed over it as if it was obvious. His choice felt like a personal slight. Complicit in a presumption that life with physical limitation was less of a life, one that could be extinguished with the mercy of putting a sick dog out its misery.

Five years later I was dedicating a Guardian column to defending a disabled person's right to die.

I'd like to say the change came from discussion. From hearing the opposition and conceding to rationality. Truth is, the problem was never too little rationality. It was too much emotion. There's something about listening to another disabled person's desire to die that touches the pit of your stomach.

If a Daniel James case emerged today, I'm not sure I'd feel any different than I did back then. His was the extreme end of assisted suicide in a debate I don't think anyone has all the answers for. But as time went on, and other cases emerged, I became sure blanket bans didn't do the issue justice, and certainly not because I felt another person's choice for death was a reflection on my life.

Sometimes, I think, changing your mind requires a change in your gut.

Ian Leslie

Before and for some time after the 2003 invasion of Baghdad, I was convinced that military action was the only way to deal with Saddam Hussein. Then, at some point during its long, bloody and WMD-free aftermath, I came to see that it had been a terrible mistake, and thus found myself in agreement with a lot of people I thought were wrong about almost everything. I won't lie to you: that was galling.

But who I am to judge? On probably the gravest political issue of my adult life, I made the wrong call. Perhaps surprisingly, this doesn't seem to have dented my confidence in my own judgement. When I find myself part of what Mrs Merton used to call a “heated debate” about, say, Syria, I don't raise my hands, smile ruefully and say, Guys, I'm going to sit this one out. I just can't be trusted. I jump in with both feet. Sometimes I make hand gestures.

According to the psychologists, a certain margin of self-delusion is necessary for our mental well-being. Most sane, happy people are wrapped in positive illusions, and one of them consists of a feeling that we're basically right about most stuff, most of the time, because we are smarter than most cookies. Empirical evidence to the contrary can wake us from this happy dream, but not for long.

Then again, maybe I'm wrong about this, and I've been right all along about everything. It's worth considering.

Jonn Elledge

Ten years ago or more I came perilously close to ruining a party by having an argument with my then girlfriend about (I'm sorry; I'm so sorry) the Euro. She was anti; I was pro.

I was very pro, in fact. “Britain should join it” levels of pro. “Happy to ruin parties by banging on about it” levels of pro, even. I claimed to be beset by terrifying visions of London's economy upping sticks and moving to Frankfurt, purely because of our silly backwards currency, but that wasn't the real reasoning behind my opinion at all.

My real reasons for being pro-Euro were entirely emotional. I was annoyed at foreign media tycoons who spread lies about the EU for their own personal reasons. I was, and am, embarrassed about Britain's petulant Euroscepticism, and our constant threats to take our ball away from a sensible, if flawed, international project. Support for the Euro was a way of showing that I wasn't one of those people.

And I was completely wrong.

Everything that annoyed me then still annoys me now, of course. I'm still pro-European, and I still cringe whenever ministers start talking about the EU like it's nothing more than a foreign enemy that it's our patriotic duty to hit with a stick.

But everything that has happened since, in Greece and Ireland and Portugal, has convinced me that joining an international currency on that basis would have been a bloody terrible idea, and that perhaps the best thing Gordon Brown ever did was to keep us out. In 2003, I now realise, I had no idea what I was talking about. I just wasn't clever enough to hold that opinion.

My pro Euro stance, in fact, was a mirror image of the little Englander Euroscepticism I professed to despise. Given that, I'm bloody glad I've grown out of it.

Helen Lewis

For years, my opinion on everything from Page 3 to pornography to prostitution was this: if both sides in the transaction are consenting adults, what business of mine is it to have an opinion?

Recently, I've realised that was a cop-out, driven by my desire to be seen as "pro-sex", i.e. not one of those dried-up old husk battleaxes of the second wave that everyone enjoys being mean about now. In my desire to seem edgy and cool and un-Mary-Whitehouse-like, I'd become the living embodiment of that Onion article: Women Now Empowered By Everything A Woman Does.

Now, my position is different, although still wishy-washy enough that it won't please either "side". I think that, as someone who lives in a world where porn and sex work happen, I do get to have an opinion. (I just need to figure out what it is.)

I've got this far: I don't think that sex having an economic value is, overall, a good thing for women. (Yes, not all sex workers are female/heterosexual, but it seems wilful to deny the prevailing gender dynamic.) Selling sex reinforces the idea that sex is something which men want, and women have to be persuaded to give up. That's the same logic which fuels the historically conservative idea that marriage was needed to obtain sexual access to women, or the modern one that you use flowers, chocolates and nice dinners. It's all reflective of a society in which men have the money and power, and use that to get what they want.

In The Sex Myth, Brooke Magnanti counters concerns about the safety of sex workers with the retort that Arctic fishing is also a dangerous profession, but no one gets their knickers in a twist about that. She has a point - I am instinctively wary of the idea of policing female sexuality - but the analogy doesn't really hold. We don't live in a society where the foundation of most relationship is assumed to be Arctic fishing, and it's generally accepted that men like Arctic fishing more than women, and if women don't give them all the cod and haddock they need, they'll be forced to fish elsewhere.

While my view on sex work has changed, though, what hasn't altered is my belief that harm reduction is what all feminists should be aiming for. As my colleague Laurie Penny says, inviting media along on raids on brothels risks compromising women's safety, and the Proceeds of Crime Act is open to abuse. If legalisation makes sex workers safer, then that's the way we should go. And we shouldn't stigmatise and ostracise sex workers: who among us hasn't contributed to oppressive systems in our lives? Let she who scrupulously boycotts every tax-dodging firm and forsakes all battery chickens cast the first stone.

Juliet Jacques

I’ve always been open to changing my mind, having spent my entire adult life somewhere on the left but unable or unwilling to identify myself with any of the post-Marx positions, let alone any party or movement that represents them. In the run-up to the US election in 2004, I found George Bush’s depiction of John Kerry as a “flip-flopper” absurd: he reconsiders his position according to new experiences and changing situations! How can anyone trust him? Bush won Ohio, and thus the US, but my faith in American democracy had been sorely shaken by the rumours about Bush’s victory in Florida four years earlier (and I spent a lot of time as an undergraduate laughing along with Bill Hicks’s take on the subject).

But looking back, few of my political opinions have shifted much since I was an angry student, even though pretty much everything else in my life has. I still think alternatives to capitalism are desperately needed, and that Labour’s shift to neoliberalism is a disaster; that the Iraq war was illegal, ill-judged and wrong; and that LGBT politics should not purely assimilationist.

Under Blair, I often said that the two major parties were exactly the same, although since studying Attlee and Thatcher as a History student, I was careful to remember that this was a recent development. This position, similar to Russell Brand’s now, was one reason why I didn’t vote in 2001, but another was that baseball cap-wearing, fourteen-pint-drinking Conservative leader William Hague was clearly unelectable, and if the opinion polls had been closer, I might have roused myself from my skunk-induced stupor to register in Manchester.

I’d always loathed the Conservative Party, even though I’d never known any Tory government besides the slow, hilarious collapse of John Major’s. But since May 2010, I’ve despised them more every day, which I suppose is a change of sorts. For the last two general elections I was living in Brighton and voted Green as they had a chance of winning a seat – and I was glad to contribute to Caroline Lucas’s success three years ago.

I still think there are too many similarities between Conservative and Labour, but now attribute them to the stranglehold that various financial and industrial interests have over parliamentary politics, rather than who enters each party at grass-roots level, and after 13 years of New Labour and three years of the Conservative-led coalition, I’d rather have the former – I don’t think the assault on the public sector, benefits or the NHS, nor the rises in tuition fees, would have been quite so brutal, even though I know that these are extensions of Blairite policies.

So, in 2015, acknowledging the sad reality of being away from a place where voting Green or Socialist would make much impact, I will probably vote Labour, albeit with the heaviest of hearts.

Unless I change my mind at the polling station ...

Sarah Ditum

One of the problems with writing about feminism is that there are very few people who want to hear about violence against women. However, it is possible to overcome this rule of silence, and the way to do it is this: initiate a discussion of pornography. Instantly, people will demand to know how feminist energies be squandered on causes such as Lose the Lads’ Mags or No More Page 3 when there are lives to be saved, rapes to be prevented.

I know this because it’s an argument I’ve chucked about myself on occasion. It is, I think now, a completely flawed one, but seductive – because it releases you from the imperative to be critical of pornography, and being critical of pornography is never a super-fun position to take. You are, after all, impinging on someone else’s pleasure. Dan Savage, whose writing on sex I enjoy a lot, is insistent about defending straight men from “smut shaming”, and who wants to be the girl who smut shames? It’s much simpler to adopt a studiously liberal position that gives preeminence to the rights of consumers and producers.

But it’s also insufficient: all of us live in a world where the messages of pornography shape our most intimate relationships. Much of the “proof” presented to show that porn is inherently damaging is more than a little flawed, but there is convincing evidence that lads' mags, for one, promulgate the attitudes held by rapists. That doesn’t mean pornography is a direct cause of rape, of course, and it doesn’t mean I think you’re a bad person for liking porn, but it does mean we should acknowledge that much of the pornography currently on offer is liable to be complicit in the attitudes that cause rape and violence against women – and that seems to be true even when the material in question doesn’t portray rape or violence.

It’s customary for anyone making these arguments to be accused of being anti-sex, specifically anti-male sexuality. But pornography as it currently exists is not an inevitable expression of male sexuality: it’s one that’s been chosen, and one which encodes a story about female subordination to masculine pleasure. It is largely directed by men, made by men and viewed by men. Of course you can find pornography that doesn’t just replicate the crudest impulses of patriarchy, but you have to go looking for it: the great mass of explicit material, including the stuff that is respectable enough to be sold through newspapers and supermarkets, just doesn’t see women as people.

That’s not because representations of sex are inevitably dehumanising of women. It’s because, as things currently stand, we’re still blinking into an awareness that women are capable of and entitled to agency and pleasure in sex. When we don’t teach consent as part of sex and relationships education, when boys are given the message that sex is something you take from girls and something that comes entwined with contempt, of course there are teenage boys who feel entitled to take, demand and share explicit pictures of girls. Why wouldn’t they when the broad social tolerance of porn comes with no provision that women are equal participants?

What’s the answer to this? I support the campaigns to get pornography off supermarket shelves and newspaper pages; I’m less keen on porn blocks and direct censorship, which seem liable to failure and corruption. Maybe what we need is more porn but of a very different kind: Cordelia Fine makes the half-wry suggestion that “Until we have [a] just society, only women are allowed to make porn and watch it. Then, once we’ve got equality, proper equality, men can join in.” Whatever the solution, though, I’m no longer happy with not asking the question. Criticising porn isn’t a distraction from making women safe: it’s a necessary part of creating a world where being female doesn’t mean living in the shadow of violence.

Update, 12.29pm: We've had a late entry by Willard Foxton. It was too good not to add here. . .

Willard Foxton

I used to be a Climate Change denier. I thought the whole thing was made up by the Green Lobby - it seemed, conveniently, to fit exactly their goals. Also, things like the fact glaciation and a "new ice age" were being confidently predicted in the 1980s made me fundamentally sceptical about the whole thing.

I remember two distinct phases of realising I was wrong - firstly, when I put my oh-so-clever "Well, glaciation was the big fear in the 80s" point to a Tory friend who also happened to be a climate scientist who pointed out computer models done on 1980s computers were a hell of a lot worse than ones done in the mid 2000s.

The second, more visceral point was when I was involved with a campaign to have a child name an Iceberg as part of the Hay Festival. Icebergs aren't named you see, they are numbered, and we thought that was rather a shame. A truly huge iceberg broke off the icecap - I seem to recall it was about the size of London - and my job was to track it. My boss at the time had a morbid fear that an ocean liner would crash into it, you see.

At the time it broke off, it was the biggest iceberg on record; by the time it was named (the child in question called it "Melting Bob"), it was the 4th biggest on record - because three bigger ones had broken off. One was about the size of Belgium. I realised if we were getting bigger and bigger icebergs, something must be going on, and all these scientists probably knew a thing or two.