On the one side, there will be those who take a hard stand against it, but their hard arguments tend to be brittle ones too. To merely argue that it is illegal begs the question of why it should be illegal, and why the age of consent has been set where it is. When pushed, sometimes these strong opponents of sex with teenagers resort to hurling names  e.g. "paedophiles"  which does not add to any further understanding of the issue.

On the other side are those who recognise that reality is complex. Some teenagers are precocious and very resourceful. They know to trawl for sex, and when encounters between adults and minors take place, it isn't always clear who the initiator is and who the respondent. Yet other teenagers are clueless, but easily seduced. And then there is an eternal fact: teenagers experiment sexually with each other. Unfortunately, it's very easy to be bogged down by all that complexity and end up with no coherent view on the matter.

There is also the question of the socio-cultural context: How does the society in which the teenagers grow up view sex? It is not true that all societies view sex in the same way. Societies heavily influenced by Christianity and Islam, sometimes through secondhand routes, e.g. middle-class India that has absorbed Victorian prudishness without absorbing Christianity itself, tend to see sex as dirty and socially destabilising. Typically, these societies see accord great social value to virginity and fidelity. For convenience, I call these the sex-phobic societies, even though the term is not quite accurate.

Yet sex-saturated contemporary culture is everywhere, not to mention peer pressure and the rush of post-pubescent hormones.

In societies that are sex-phobic, the contradictions between social expectations and desire are greater, hence teenagers are typically more troubled by the choices they face, and if they make a choice that they later regret, that regret runs more painfully than for a similar teenager in a culture that does not treat sex with deterministic importance.

That said, let's turn back to the question of law. Actually, let's not turn so quickly to law, for law does not exist in isolation.

It is more fruitful to examine the ethics of sex with teenagers, and then to see whether the laws of our country are consistent with it.

The ethics

Adults have many advantages over teenagers. We generally have more money and better social skills, but very importantly, maturity brings with it better control over our own emotions, resulting in more deliberate decisions and actions. We also have a wee bit more insight in the psychology of teenagers, having been ones ourselves.

Any relationship between an adult and a teenager is therefore an asymmetrical one, and naturally, responsibility for how that relationship is manifested must fall much more on the adult than on the teenager. Asymmetry means the potential for exploitation is there.

Ethical behaviour requires us to be cognisant of this asymmetry and to avoid putting others in disadvantageous situations. It is fair to expect self-control.

The general rule is this: the greater the asymmetry in maturity, the greater the asymmetry in responsibility. A 15-year-old experimenting with a 14-year-old is one thing; a 40-year-old having sex with the same 14-year-old is quite another. Even an adult over 30 having sex with a 17 year-old, while legal in many places, would be quite borderline ethically-speaking.

The law

Unfortunately, the law is a blunt instrument; it has only two states  legal and illegal  when the world is analogue. Yet, in practice, the law can be nuanced. Therefore a meaningful discussion of this topic requires attention not only to what the law says, but also how it is used.

What do we look for when we want to evaluate if the law is consistent with ethics and social reality?

First, there is the age of consent, and once again, it is necessary to be discerning. In Singapore, there are generally two ages of consent. For example, the age of consent for lesbian and heterosexual sex is 16; likewise for heterosexual marriage under Syariah law it is 16 too. For heterosexual marriage under civil law, it is 18; for commercial sex, it is 18 too.

The anomaly is male-male sex. It remains illegal regardless of age, but the government has openly said the law will not be "pro-actively enforced" in consensual situations between adults. However, it has never defined what "adult" means.

Is sixteen an appropriate age of consent? I think so. By that age, the most turbulent phase of adolescence would be passing, with emotional maturity beginning to set in. The individual should also be sufficiently informed, either through schooling or by parents, of behavioural norms and health risks. Sixteen too is the age when it is legal to work in Singapore  this means money in the pocket, mobility around the city and a socially recognised independence.

But this doesn't mean the law should treat a 16-year-old having sex with a 15-year-old the same way as a 46-year-old and a 15-year-old, though both relationships may be technically illegal. Common sense tells us the risk of exploitation is much greater in the latter case than the former. This is where the law has to be nuanced by intelligent sentencing.

Similarly, the law should not treat a 28-year-old having sex with a 15-year-old the same way as a 28-year-old with an 11-year old. We should of course recognise that a 15-year-old has more capability to stand up for himself or herself than an 11-year-old. Again, differential sentencing should reflect this.

So, the second thing to look for in your jurisdiction is the pattern of sentencing. Is it one-size-fits-all? Is it carefully differentiated depending on circumstances and the age gap? Does it take into account coercion, inducement and deception? Does it take into account mental age in cases where the younger person is intellectually impaired?

Even when sentencing is differentiated, yet another question arises: How much penalty is enough for each situation? There is no easy answer to this, unfortunately. I think much depends on a society's cultural bias. How much does a society value teenage abstinence and virginity? If it values it highly, then any teenager who does not live up to it may suffer severe social and emotional costs. This would argue for heavier penalties on adults who breach the law, the better to deter.

Conversely, in societies that are more tolerant of sex, one can argue that the social and psychological damage to young teenagers is less, and highly punitive sentences would be disproportionate.

In conclusion, what I'm saying is this: This subject, lying as it does at the intersection of law and human behaviour, does not lend itself to easy answers. Adopting a black-and-white, moralistic tone is never helpful. Neither is adopting an attitude that refuses to recognise that young people are vulnerable however "grown-up" our modern culture may cause them to appear. We must recognise that we have a responsibility towards them, both at a personal level and socially, through our laws.

What is needed is critical thinking, coupled with the caveat that ultimately we are dealing with social constructs. But most important of all, there has to be a sense of humanity. After all, sex resides at the heart of our lives, and as much as we think we are wise, in this world, each of us also takes turns at being foolish.

Alex Au has been a gay activist and social commentator for over 10 years and is the co-founder of People Like Us, Singapore. Alex is the author of the well-known Yawning Bread web site.