Madam, - Séamus O'Callaghan (March 4th) says that the dictionary defines marriage as a union between a man and a woman; but marriage is a legal concept whose definition has changed repeatedly over the centuries.
Until recently in Ireland is was defined as an irrevocable union between a man and a woman. For centuries, rather than being united in law, a woman was basically seen as the property of her husband. In many societies men are allowed to take multiple wives. Until recent times in the United States marriage was defined as a union between one man and one woman of the same race.
So the definition of marriage changes throughout the ages to meet the changing requirements and attitudes of society.
We now live in a society where many people live in committed, loving relationships with people of their own sex. Many bring up children together, many don't - just as many opposite-sex relationships are also childless. There is no argument for treating these relationships as any different under the law .
Same-sex marriage is an idea whose time has come. - Yours, etc.,
PETER FITZPATRICK, Darlinghurst, New South Wales, Australia.