Statistical arguments are very popular with Irish Catholic writers at present. Here’s Michael Kelly of The Irish Catholic claiming that abortion should remain illegal because Ireland is the safest country in the world to give birth. David Quinn of the Iona Institute has claimed that marriage equality should not be extended to gay people as children of gay couples are statistically worse off than those in “traditional” families (not true says Ruadhrí).

Writing recently about basing political action on religious beliefs Quinn suggests that to do so should not be objectionable to the secular-minded as far as the religious beliefs are amenable to reason. Presumably this means leaving aside the supernatural elements in favour of the natural, and this focus on statistics may be a manifestation of this approach.

If we accept the statistics for the sake of argument, we can focus on the logic, which is this: if a behaviour is sub-optimal then it should not be permitted.  It might be argued that the sub-optimal outcomes are part of (rather than forming the sole argument of) the Catholic case based on other ethical factors. Nevertheless, it is a strangely utilitarian form of morality from such quarters.

To follow this line of reasoning beyond Catholic sexual morals, we could consider, for instance, that cycling statistically extends your life by several years (ban all other forms of road transport), vegetarians are less likely to have heart disease (ban meat), bilingual people are less likely to get Alzheimer’s (ban monolingual parents), atheists are less likely to end up in prison (ban religion), religious people are more likely to be happy (ban atheism). Are we as a society willing to tolerate such forms of voluntary (allegedly) sub-optimal behaviour? I would say yes, provided they don’t lead to real problems such as child neglect or climate destruction.

If Quinn, Kelly and fellow-Catholics are serious about evidence-based policy they will need to do more than cherry-pick studies which confirm their religious beliefs and actually weigh up evidence related to many factors and outcomes, and rather than proposing illiberal policies based on marginal statistical differences, one would expect citizens of a republic to show more respect for personal liberty.