When, this week, you read a headline saying, Ireland to legalise abortion; or see a statement from the Catholic church saying "Irish abortion reform is a 'licence to kill innocent babies'", you should treat it with great scepticism. For a start, nobody has suggested changing the law, nobody's legalising anything, and innocent babies have more to fear, as ever, from the Catholic church, than from any Irish abortion providers.

Nobody has suggested, even out of respect for the recently killed Savita Halappanavar, the slightest modification in the law, so that an abortion might be permitted in a case where the mother would probably die without it, and the foetus would probably die regardless. There are no new ideas, and no concessions to anybody – all that's been mooted is the codification of a supreme court ruling, so that the abortion provision they do have is no longer just precedent, it's actually enshrined in law.

Civil liberties and family planning organisations are rejoicing, quietly, nevertheless. To understand why this looks like progress, we need to consider how it looked before.

Ireland has the strictest abortion rules in Europe, most of them framed in, and unchanged since, 1861. The maximum sentence for performing an abortion is a lifetime of penal servitude – they are still using law so antiquated that if they ever wanted to enforce it, they'd have to build a bespoke hard labour camp.

However, in 1992, something did change: in the case of the attorney general versus X, the Irish supreme court decreed that a woman could seek an abortion if her life was at risk, including the risk of suicide (Miss X, incidentally, was 14 when she was raped by a neighbour; no provision exists in Irish law for the termination of pregnancies that result from rape or incest). On the ground, this made very little difference: the possibility of suicide is almost never recorded as the reason for an abortion, and the handful of terminations that do take place in Ireland annually are justified by imminent physical threat to the mother's life (not, you'll notice, her health).

So anyway, that's parliament's big idea: to turn the X decree into a constitutional reality. Short of doing nothing at all, it's the limpest thing they could possibly do. And yet it's the first time in two decades that mainstream Irish politics has had the courage to get anywhere near this issue. To judge from their reactions, both sides, pro- and anti-choice, believe this to be the first step towards legal abortion.

While the defence of threat to the mother's life existed only in a theoretical ruling, doctors would have had no faith in it as a protection against prosecution. But if it's part of the constitution there's a chance it will become less a matter of having to prove suicidal intent and more a matter of the doctor's discretion. From there, it's not a hugely long journey to the situation we have in Britain, where you simply have to get two doctors to attest to the fact that the pregnancy is jeopardising your mental health.

It's unknowable whether Ireland would ever make that journey – from requiring the imminent threat of the woman's suicide to the more nebulous requirement of a threat to her mental health – and if they did, how long it would take. But it strikes me how perverse this is, that we have to hold up mental turmoil in order to be allowed reproductive self-determination. And I am struck again by how insulting even the British system is to women, let alone the Irish one.

The whole business is laced with irony – terminating a pregnancy is, in all likelihood, the rational response of a person making a decision for the long term, and yet in order to have it enacted, you must present yourself as dangerously unstable. Over time, all women who seek an abortion have come to be characterised as "vulnerable"; I've noticed over the past couple of years that just the act of becoming accidentally pregnant is enough to taint a woman as volatile or chaotic (rather than "fertile").

This profoundly damages our standing in debate – in asking two doctors to sign off on our imperilled sanity, we undermine our plausibility as reliable witnesses. It's not shame in the act of abortion itself that quiets us – it's shame at having had to lie about our psychic condition, and a sense thereafter that we are less than robust. I don't think it's an accident that no female MP has ever admitted to having had an abortion.

This leaves a vacuum where mainstream opinion should be (one-third of women have had an abortion; 76% of people are in favour of legal abortion); nature, abhorring the vacuum, fills it with Nadine Dorries, for which I suppose she (that is, nature) would say we only had ourselves to blame.

The tendency with the abortion debate is to consider the anti-choice lobby as more sensitive, more governed by their consciences and anger than the pro-choice lobby. It's true in some respects – the Roman Catholic church certainly has a tendency toward hysterical overstatement. And yet we pander too much to anti-abortionists, taking whatever scraps of reproductive rights they'll throw us, stopping the fight as soon as our immediate pragmatic needs have been met. In some ways, this is as true in Britain as it is in Ireland. We all need to rediscover the spirit of 1967.

Twitter: @zoesqwilliams