In his letter yesterday, Mr Darius Lee said that biologically, human reproduction requires the sexual complementarity of a man and a woman ("Marriage should be reinforced, not redefined").
This implies that the sole purpose of a marriage is to reproduce.
This cannot be, for already, infertile heterosexuals are not denied the right to marriage.
Heterosexuals who do not want to have children are also allowed to marry.
The law does not question the ability or desire to have children as a prerequisite for marriage.
So why should this be a barrier to same-sex marriage?
Mr Lee added that studies on the differences between same-sex and different-sex parenting suffer from various limitations and are inconclusive. But some studies have found there is no difference between children raised by same-sex parents and those raised by different-sex parents.
The letter, as a whole, implies that marriage is an institution that has not evolved over the years.
That is a view that ignores the reality of history and culture.
Marriage in the past involved polygamy, not monogamy.
Marriage in the past did not put women as equal partners. Marriage in the past - and in some parts of the world still - was transactional, with women seen as commodities.
Divorce is a relatively new concept, but is now seen as a right that protects women.
The list goes on.
The concept of marriage is artificial and changes over time. It is not a universal concept. Love is.
Angeline Wong Hui Wei (Ms)