For this reason God gave them up to vile passions. For even their women exchanged the natural use for what is against nature. Likewise also the men, leaving the natural use of the woman, burned in their lust for one another, men with men committing what is shameful, and receiving in themselves the penalty of their error which was due. (Romans 1:26-27 NKJV)

The definition of the ambiguous word “natural” comes up very often when discussing homosexuality and the above passage from Romans. There are, however, many different and nuanced views of what “natural” means, not only in this context, but in general usage, which pertain to the question of the origin and morality of homosexuality.

The three possible understandings of “natural” include extant (occurring in nature), biological, and designed. Let’s explore them.

1. Natural: Occurring in Nature

There is no doubt that homosexuality exists in the natural world – not only in humans, but in animals. For some, this argument alone is enough to justify the normality or morality of homosexuality in humans.

But this logic is flawed – we cannot merely look at nature and assume that all that happens in the animal kingdom, or the human one, is moral. Male lions kill the cubs of competing males, male chimpanzees rape female ones, and theft is a constant theme in nature. So this line of reasoning is ill advised.

2. Natural: Having Biological Origin

This argument is a subset of the previous – that is, if something has a biological origin, it must be morally acceptable, or at least normative and immutable. How could you fault someone for a trait that they have no control over?

Regarding this argument in general, we  might argue that just because a condition or behavior has a 100% biological origin does not make it morally or practically positive or neutral or bad. And as we shall see, homosexuality is at most 40% genetic, and perhaps only 10%. But researchers are also looking into hormonal factors that may not be reflected in mere genetic percentages.

But assuming 100% biological origin, what can we conclude with regard to arguments for or against homosexuality from this avenue?

a. Biological Diseases (Bad)

For example, some cancers are entirely biological in origin, and we consider these threats to mortality a bad thing. So part of how we would refine biological logic is to ask if it increases mortality or morbidity.

With regard to homosexuality, the argument from higher morbidity exists, though it is not conclusive. That is, gays are more likely to attempt suicide, suffer depression, and engage in domestic violence, as well as suffer mental illness and diseases. 1

The immediate consideration might be that social rejection is responsible for much of these negative behaviors (including the promiscuity which attends much male homosexuality and leads to disease), but negative social factors and promiscuity do not explain all of the increased morbidity.  2 3 4

Homosexual men differed from their heterosexual counterparts on all four suicide symptoms (OR ranging from 2.58 to 10.23, with higher ORs for more severe symptoms), and on the sum total of the four symptoms; homosexual women only differed from heterosexual women on suicide contemplation (OR=2.12). Controlling for psychiatric morbidity decreased the ORs, but among men all associations were still significant; the significance for suicide contemplation among women disappeared. Younger homosexuals were not at lower risk for suicidality than older homosexuals in comparison with their heterosexual counterparts. Among homosexual men, perceived discrimination was associated with suicidality. This study suggests that even in a country with a comparatively tolerant climate regarding homosexuality, homosexual men were at much higher risk for suicidality than heterosexual men. This relationship could not only be attributed to their higher psychiatric morbidity. In women, there was no such clear relationship.  5

The bottom line here, however, is that while homosexuality is correlated by greater morbidity and mortality, it’s not clear that this correlation means anything either morally or causally, and homosexuality is not obviously degenerative or crippling. So this argument is not strong against homosexuality from the disease argument. Homosexuality is not a disease.

b. Biological Deformities (Morally neutral but still deformity of natural function)

Some biological physical traits are clearly deformations, like missing limbs or other handicaps like blindness and deafness. We make no moral judgments on the blind, so perhaps homosexuality could be seen as a biological dysfunction.

What would support this hypothesis?

  1. Transgenderism is treated as a biological mistake:  if we are willing to treat transgenders with hormones and surgery, why is homosexuality not the same? This approach confuses gender identity with gender orientation, and most/many  homosexuals don’t feel alienated from themselves, so this argument fails as well.
  2. Behavioral Sterility: Modern technology aside, gays cannot reproduce with one another. But technically, this sterility can not be seen as a biological defect – their actual sexual apparatus works. However, their orientation which RESULTS in sterility could be seen as a dysfunction. Which leads to our next point.

c. Biological Behaviors

While many of our personality traits are directly formed from our biology, many are influenced by our environment. But what about self-destructive or criminal behaviors like alcoholism, attention disorders, or aggression, which we know have some biological roots?

When we assume (for sake of argument) that homosexual orientation is a possible dysfunction (because it leads to behavioral sterility), and add to it the environmental factors that are correlated with homosexuality (increased rates of childhood sexual trauma, negative identity formation due to bullying or rejection, etc.) the argument for homosexuality as a reactive dysfunction  gains some traction. Even if biological influences are considered neutral, the high correlation of homosexuality with other highly negative formative experiences may indicate that it is a disorder. 6

Even if biological influences are considered neutral, the high correlation of homosexuality with other highly negative formative experiences may indicate that it is a disorder. But this does not mean directly that biological same-sex orientation is a dysfunction per se.

Bottom line? Homosexuality can be logically viewed as a dysfunction, and therefore unnatural due to decreased behavioral fertility and higher morbidity (so not a disease per se, but a deformation). But the data and the argument are not conclusive.

d. Biological Variation

Since no obvious and direct detrimental effects can be associated with homosexuality, it is hard to argue definitively that homosexuality is not merely a normal biological variation. Yes, it is correlated with higher morbidity, and yes, it is associated with behavioral sterility. However, that is not enough to argue against it.

Some argue from a Darwinian perspective that homosexuality may be either (a) a way for nature to weed out bad genes from the gene pool, i.e. natural selection, or (b) if gay genes exist, they may have other survival advantages. 7 8

Summary of a Biological Definition of “Natural”

Homosexuality can not be viewed as normative just because it occurs in nature. Becuase it is not directly deadly, it can’t be argued to be a disease. There are some good arguments to address it as a dysfunction, but these can not be argued from biology, but only behavior and psychology, not the least of which is because homosexuality has not been shown to be biologically determined. Homosexuality could be viewed as a normal variant, but a Darwinian argument can be made against it due to behavioral sterility. However, some are also attempting to construct evolutionary arguments for homosexuality as well.

3. Natural: By Design

From a Biblical perspective (Romans 1:26:27 above), this is the argument made by the Apostle Paul. Homosexuality is against the “natural use,” i.e. the design of male and female. Some theologians attempt to make this “against THEIR nature” (against their orientation), or alluding to temple prostitution, forced homosexual penetration as was common in the Roman army initiation rituals, or pederasty, but these arguments seem out of step with both the immediate text and the rest of the scripture’s condemnation of sexual sin, including and perhaps especially homosexuality. 9 10 11 12

a. Argument from Design 1: Biological function and pairing

This argument goes simply that reproduction is essentially the biggest miracle of our world, and a primary and formative part of an organism’s definition. It is so complex and finely tuned that it had to be designed, and other sexual pairings violate that obvious design.

The inability to procreate, as well as the anus’s unsuitability for penetration (both in thickness of the lining and it’s excremental content) also argue against the most common form of gay sex.

b. Argument from Design 2: The Bible and God’s Intent for the Sexes

When Jesus is asked about marriage, he refers his listeners back to the creation story, mentioning only Adam and Eve. Not only is this a direct rebuke to divorce (the direct context), but indirectly, to polyamory and all other forms of sexual mis-conduct.

And He answered and said to them, “Have you not read that He who made them at the beginning ‘made them male and female, and said, ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’ So then, they are no longer two but one flesh. Therefore what God has joined together, let not man separate.”(Matthew 19:4-6)

It is notable that in the Genesis narrative Jesus is mentioning (Genesis 3:27), being male and female is part of the image of God (as well as dominion over creation). This may explain why Paul sees the violation of male-female pairing as replacing the image of God (Romans 1:22-23).

Summary of the Design Argument for “Natural”

Not only is this the strongest biblical argument, it is also the sense in which Paul is arguing about the violation of nature in homosexuality.

The intended design and biological morbidity arguments are essentially the same, and together hold some weight in these discussions.


Many arguments over a natural law morality can be avoided if we clarify what we mean by “natural” – extant, biological,  or designed. The Bible, in my mind argues from the design perspective, and all ethical arguments based on functionality or morbidity must be seen as secondary, but still of some value in the discussion.