Natural Law on Sexual Ethics

• To Aquinas any sexual act that does not achieve reproduction or attempt to achieve reproduction is not achieving its telos. This logically leads to secondary precepts that rule out homosexuality, masturbation and artificial contraception.
• One of Natural Laws primary precepts is reproduction.
• Aquinas believes marriage has 2 functions and is necessary in maintaining an ordered society. One function is the 'generative' function of bring new life. The other is the 'unitive' function of bringing a couple together. These purposes cannot be separated. This has influenced Roman Catholic thought.
• In addition to Aquinas' belief in the necessity of marriage which rules out extra-marital and pre-marital sex. Extra-marital sex is further disputed for Aquinas by the ten commandments, one of which states that adultery is wrong.
• John Finnis is a modern natural law philosopher who says that certain things in life are basic goods of human flourishing. These are reproduction, knowledge, work, friendship, spirituality etc. He argues marriage is also a basic good as only in marriage can friendship and reproduction be combined. On homosexuality he argues that this cannot bring together with the giving of life and thus is instrumental and harmful.
• In focussing on marriage and on reproduction , Natural law avoids cheapening the act of sex, like some liberal views.
• There is some evidence to suggest that children of married parents are more likely to flourish in education. It could be argued a stable environment is important for raising children.
• Natural law is derived from divine law. If God doesn't exist then there is simply no reason to observe the precepts. However, some theologians argue that natural law is built into the universe and so would exist even with an absence of God.
• Homosexuality is simply a part of some peoples nature. They have been born without heterosexual inclinations. Similarly, even if it is to deny that homosexuality is natural than it is committing a naturalistic fallacy by assuming that just because something is natural, it is good.
• Natural laws focus on reproduction renders sex between infertile people and elderly people as pointless. That seems unfair.
• Natural Law is when interpreted through church teachings is overly legalistic. It has not moved with the times in terms of advancements in reproductive technologies.