ANALYSIS: Tory ignorance of Ireland is embarrassing - and dangerous
Displaying an eight-year-old's level of understanding of Irish politics is only acceptable if you happen to be an eight-year-old.
But if you are the former leader of the Opposition, an ex-Cabinet minister and someone who, as a second lieutenant in the Scots Guards served in Northern Ireland, then unfortunately that defence no longer applies.
Step forward, Iain Duncan Smith. On Channel Four News last week, he opined that the reason Irish PM Leo Varadkar was playing hardball over Brexit was because "the presidential election is coming up" and his party, Fine Gael, is under pressure from Sinn Fein.
That rather ignores the fact that the presidential election that is still a year away, and that whoever wins will perform a largely ceremonial role in Ireland's parliamentary system.
Still, let's give him the benefit of the doubt and assume that IDS mis-spoke and was actually talking about the prospect of a snap general election, which many predict will take place in the spring.
Sadly, however, any suggestion that that was the case evaporated when he was interviewed by the BBC's Laura Kuenssberg last night and declared: "You know this Irish stuff was not at this state some months ago, now its suddenly become an issue because the Irish for political reasons internally, presidential elections ..."
The sound of jaws hitting the floor from Donegal to Galway could be heard across the Irish Sea. Sometimes it really is better to be thought a fool than to open one's mouth and remove all doubt.
To be fair to Duncan Smith, however, he is not the only Tory Brexiter to display an attitude towards the Republic which is ignorant at best and cavalier at worst.
Nadine Dorries yesterday decided to wade into the DUP's spat with Theresa May over the Irish border by heaping praise on the the Ulster unionists who, she suggested, were once again displaying the tactical nous they used to such great effect over the Good Friday Agreement. The only snag in that argument being that they were the only major political party in Northern Ireland not to support it.
Jacob Rees-Mogg, seen by many as perhaps the most cerebral MP on the Conservative backbenches, has also taken a rather slap-dash approach to the tricky issue of the Irish border. There is no need for a return to customs checks along the 310-mile frontier after Brexit, he has insisted, and if a visible border is created it will be the fault of the Irish and the EU.
Two former Northern Ireland Secretaries - Owen Paterson and Theresa Villiers - have taken a similarly breezy attitude to the issue. Only this morning, Villiers said all that was needed was "goodwill and technology" to solve the conundrum. Well, it is nearly Christmas.
As the Brexit talks progress, suspicions are growing that those in favour of removing the UK from the European Union may not have thought through all of the implications in as much detail as they might have. Nowhere is this lack of forward planning more evident than on the Irish border.
The Good Friday Agreement is nearly 20 years old, and has required constant nurturing in order to sustain it. And it is by no means inevitable that a visible border between the Republic and the North will lead to a resumption of hostilities.
But the attitude displayed by many on the Conservative benches suggests they have given little thought to the consequences of what they are proposing. Some of their comments on the subject have not just been embarrassing, they are also potentially dangerous.