Please partner with us as we serve Canadians during this difficult time


We do not need an authority to know whether the sun or moon exists. We just look. Granted, researchers can provide us with further details about these objects, but we know they exist. The same is true about biological sex. In nearly all cases, nature reveals the distinguishing features of the sexes.

Men and women differ biologically. This is another way to say that nature distinguishes men and women. Granting this is so, how should the concept of gender relate to sex? 


To start out, we should need to understand nature because sex exists naturally. The deer grazes and procreates for the preservation of its species. It is the way of things. Nature embeds purpose into sex. 

We can and should say more than this. The bee seeks to gather nectar to support its hive. Yet the bee also secondarily drops off pollen during its flight. So it primarily seeks the well-being of the hive and the queen (who in turn procreates) while also supporting the ecosystem. Both are purposes of the bee in nature. 

If sex has a purpose (whatever that purpose is), then it is a natural good to pursue that end. As a result, our gender expressions (i.e., norms and roles) should correspond to the natural purpose of sex and not conflict with it. Pursuing a good is better than not pursuing that good. 

While this may be self-evident, defining the purpose of sex takes work. It requires work not because it is any less self-evident than the existence of sex but because our culture has created a particular kind of “common sense” that makes it seem non-evident. Our common sense tells us that biological sex and gender constructs refer to two different ideas.


For most of us, biological sex refers to a closed symbolic system (biology) that defines a certain set of characteristics. So the male sex has an XY chromosome, a distinguishable reproductive system, a different skeletal frame, and so on. 

We nevertheless need to be honest about biological and natural sex (which are not the exact same thing—biological systems are a subset of nature). Some people possess “physical characteristics [that] are not completely male or female but somewhere in between. This includes genetic variations in the complement of sex chromosomes.” 

These exceptional cases should make us sensitive to the complexity of biology as well as more careful in how we define the nature of sex. Since I have partially done that elsewhere, I would just like to say here that natural sex differs from biological sex since the former comprises both metaphysical and physical characteristics. Biology by its very definition only makes sense of an enclosed set of biological symbols to define its object of study. 

The second idea points to our identity that may or may not correspond to the symbolic world of biology. Medical News Today explains: Gender “can refer to the role of a male or female in society, known as a gender role, or an individual’s concept of themselves, or gender identity.” While this definition may not satisfy academics, it does a good job of relaying our society’s view of “common sense.” 

Common notions

Common sense stands and falls with a society’s set of norms. We all expect to have regular electricity and to buy coffee for a set price. It is common sense that we can do this. It is common sense that water comes from a faucet. It is common sense that we can trust the police to protect us (in Canada). 

Yet other countries or other sub-groups in our country may not share the same common sense that we do. All the above concepts could be flipped on their heads or simply not exist (e.g., running water). 

Instead of common sense, we need to affirm “common notions” or the light of nature. Common notions are truths that become obvious when described accurately. Night exists because the sun sets (or the earth spins). That becomes self-evident when said. Someone could deny that night exists, but they would be seen as making an incorrect claim. 

(Yes, I know that dark technically means the absence of the light, and so in one sense night does not exist but is a privation of the sun’s illuminating presence. But you know what I am trying to say).

Other first principles exist like: the sun is not both the sun and the moon. They obviously differ. And everyone can affirm this law of non-contradiction. Reason belongs to us by nature. We are after all rational animals unlike the beasts of the world which some call irrational animals


With all that said, we can now return to the idea of purpose. In simplest terms, everyone affirms that animals live to reproduce and to flourish. Yet this purpose includes various proximate ends. A bee may gather nectar for its hive, but it also supports the ecosystem by spreading pollen far and wide. So we can broaden or narrow the purpose of anything by speaking about final and proximate ends. 

Humans have purpose too. At one level, procreation seems like an obvious end for sex. And certainly, once we have defined sexual procreation accurately, then most will have to affirm this as a common notion—at least those who have resisted the tyranny of common sense. And when defined, most will also affirm that family is the material context for procreation. Parents and children living together have such a pedigree and naturalness about it that few of us would deny the natural goodness of marriage and family. 

So procreation within a family context represents a common notion about the purpose of sex. Nature, however, has her limits. She can only tell us “that something exists” along with the embedded natural purpose of the existent thing. This is not nature’s fault but ours because of our limited capacity. 

Scriptural revelation confirms and may redirect these natural observations since it is the final authority for Christian teaching. And no matter what, it always speaks truthfully with much more clarity than nature can convey to us. In the language of the Belgic Confession (1561), the “universe is before our eyes like a beautiful book,” but “God makes himself known to us more clearly by his holy and divine Word” (Art. 2). 

By God’s grace, nature bestows upon us phenomenological experience. God through his word, however, makes himself and his works “known to us more clearly by his holy and divine Word.” Indeed, Scripture affirms what nature reveals: God created humans in his image as male and female (Gen 1:27). Adam named the woman Eve because “she was the mother of all living” (Gen 3:20). And marriage or family provides the material context for motherhood and fatherhood (Gen 2:24). 

Yet Scripture tells us a mystery that nature can only tell us murkily. We come to learn that marriage—that union of male with female—points to an ultimate end of our union with Christ (Eph 5:32). It points to our Spiritual union with the bone, blood, and flesh of Christ. 

That is to say, the ultimate purpose of sex is union with Christ. Marriage and family then provide anterior ends which may or may not be actualized to fully manifest human nature. The potency for motherhood or fatherhood alone makes one human; its fulfillment through Spiritual union with Christ alone perfects humanity. As a natural good, siring or birthing a child signifies our spiritual end—but it is not the ultimate end itself. 

Gender and sex

Someone with an XY chromosome can both affirm the goodness of marriage and not marry—if the ability to fulfill that natural good does not present itself. Spiritual union remains the ultimate fulfillment. Therefore, we should not dismiss the natural good of sex in place of an artifice of culture.

To construct a sexualized identity apart from our natural capacity means that we lose out on the natural good of marriage and family. This natural good itself points to our ultimate joy and fulfillment in Christ. To sidestep this natural good (even if we only have it in potency) means that we sidestep a sign of our salvation. Further, it could mean we sidestep a foretaste of our union with Christ which we experience through actualizing marriage. 

Our expression of gender should then take into account both our potential towards parenthood as well as our union with Christ. We should also be careful not to confuse behavioural norms for fitting expressions of sex. Some men proclaim their manliness through violence—but true fatherhood cares for others as God our Father does for us. 

On the other hand, some define gender in ways that do not even try to fit with our sexual potency. We should reject such proposals because they are not good—they inflict harm because they hide away the sign of our salvation which is good by definition. 

Natural sex, rightly defined, is a common notion whose ultimate good God reveals to us in holy scripture: union with Christ. While we may not actualize our capacity for human parenthood, we should still cherish it as a natural good and a sign of our ultimate good. Hence, our expression of gender should line up with our sexual goods in fitting ways. 

The reason why is simply because this is good. And goodness should be cherished since God is Goodness himself.