Lord Wilson of Culworth, a justice in the Supreme Court since 2011, also gave his backing to gay marriage because it would strengthen, rather than weaken, the institution of marriage.
The judge, who serves as a Privy Counsellor, said widespread divorce had created what he described as “blended families” made up of “the half-blood”.
In a speech to the Medico-Legal Society in Belfast, Lord Wilson said that as a “committed member of the Church of England” he envied the “greater strength of traditional family values in Northern Ireland”.
But he went on to give a sometimes controversial analysis of how the modern approach to love and marriage may have benefited society as a whole.
“Death has always enabled the surviving spouse to remarry but the availability of divorce preciptates many more remarriages and in their wake come many more step-families and relationships of the half-blood,” Lord Wilson, 68, said. “So the blended family now often replaces the nuclear family. I am not convinced that it is a bad thing: might it not be healthier for children to learn at a very early age to cope with relationships in a mixed and wider family group?”
Lord Wilson pointed out that same sex marriage was “not a novel concept” and had been allowed in ancient Egypt and Republican Rome.
“Then, for the next 1,500 years, Christian doctrine ... cast an irrational opprobrium upon all sexual acts other than procreative ones. In my view, the malign effects of the doctrine leave a residue even today,” he said. “Far from destroying marriage, I think that to allow same sex couples into it strengthens it; but in my view the most important benefit of same sex marriage is the symbol that it holds to the heterosexual community ... that each of the two types of intimate adult love is as valid as the other. The availability of marriage properly dignifies same sex love.”
He added that it was “not good enough” to suggest that same sex marriage was inappropriate simply because it has traditionally taken place between a man and a woman.
Lord Wilson argued that marriage was an “elastic” concept. For example, although polygamy was frowned upon in Western culture it was a “deeply rooted facet of marriage in other respected cultures”.
Marriage between first cousins is illegal in parts of the world but it is “inconceivable” that it should be banned in Britain because it is “deeply rooted in the culture of our Pakistani and Bangladeshi communities” despite the increased risk of genetic abnormalities in their offspring, he added.
Lord Wilson also pointed out that Australia allows a woman to wed her uncle, and France permits about 20 posthumous marriages to take place a year, if the surviving member of the couple can prove they were genuinely engaged. He added: “It seems bizarre but, if it really helps the broken-hearted, we have at least to ask: why not?”