Marriage is an institution involving two people of the opposite sex given "special protection", under the Constitution but the Constitution does not give same sex couples the right to marry, lawyers for the State have argued before the High Court.
The right to marry does not apply to lesbians or gay couples because the Constitution's wording on marriage unambiguously refers to a man and a woman, Paul Gallagher SC said.
Donal O'Donnell SC, also for the State, said a lesbian couple who contend their Canadian marriage should be recognised here or that they should have the right to marry here were making a "bold claim" that would have consequences if upheld by court. There was no social change or public consensus that allows the courts to redefine what was meant by marriage, he said.
The Constitution's definition did not mean someone could simply "marry the person you love". If that were the case, then the definition set out in Article 41 would be "completely malleable".
Both counsel were making submissions for the State in the action by Dr Katherine Zappone, a public policy consultant, and Dr Ann Louise Gilligan, an academic, against the Revenue Commissioners and the State.
They claim the State authorities' failure to recognise their Canadian marriage breaches their right to marry and to equality of treatment under the Constitution, European Convention on Human Rights and the European Charter of Fundamental Freedoms. They also argue that if their Canadian marriage, obtained in British Columbia in 2003, is not recognised here they should have the right to marry within the State.
The State denies the alleged breaches of rights.
Yesterday, Mr Gallagher said the Constitution's wording on marriage was "plain and unambiguous". There was nothing that would alter "the natural meaning of those words". Any interpretation that the Constitution provides same sex couples with the right to marry was incorrect, he said. There was no legal statute that allowed the concept of marriage to be radically changed, counsel argued. Marriage was an institution between two people of the opposite sex, given "special protection," under the Constitution.
Mr Gallagher said the State had not breached the European Convention on Human Rights and the European Charter of Fundamental Freedoms, as the respective European courts had also defined marriage as something between a man and woman.
He rejected the couple's claims that the tax code had unfairly discriminated against them.
Counsel further denied claims that the Revenue had acted unlawfully by refusing to recognise the plaintiffs as married for tax purposes. The Revenue had, at all times, acted fairly and openly and were subject to "unjust criticism".
Since the State decriminalised sexual activity between homosexual men in 1993, a lot of legislation, including the Equal Status Act and the Unfair Dismissal Act, had been introduced to counter discrimination against people on grounds of sexual orientation, Mr Gallagher also submitted.
Mr O'Donnell said the understanding of marriage either in 1937 or in 2006 did not extend to same sex couples. For good or ill, marriage was defined as something between persons of the opposite sex and was given special protection in the Constitution on the grounds that it forms an important part of the family - the base unit of society. The plaintiffs claim was "unsustainable", he said.
Although the Constitution does not specifically state that marriage is between man and woman or include a ban on a same sex union, it was self evident that such unions were not contemplated when the Constitution was adopted, Mr O'Donnell said.
The only way the Constitution could be changed was by the people in a referendum and this was "a clearly identifiable route". The hearing continues today before Ms Justice Elizabeth Dunne.