At the core of many debates and conflicts emerging today is how we understand the body. Relatedly, self-expression and self-determination are strong principles in our age.

And so we are left wrestling with questions such as these: Is marriage just for the self-expression of love or are there biological aspects to marriage? Is my sexuality and its orientation really tied to the nature and purpose of the body?

In the end, almost all of our moral issues surround the view of the body. Many prevalent ideas existing today contra Church teaching are rooted in the thought of French philosopher René Descartes (1596–1650), among others. Over the last 500 years, we have seen the devastating effects of Descartes and other modern philosophers. Thus, we must understand such thought, as well as the Christian understanding of the body, in order to properly respond to the issues of the day.

Descartes’ philosophy of the human person is popularly known as dualism. This means that there is no real integration between the body and the soul. They are not only two distinct entities, they are two separate entities that, while interacting with each other, are not ultimately dependent on each other. This leads to all sorts of logical consequences in human thought, action and culture that begins to slowly impact the way we experience the body. Most fundamentally, Descartes’ idea leads to treating the body as extension: by this is meant that the body is only expressive of my true inner self. Personhood becomes detached from the body, and the body begins to be seen as both a tool and canvas for self-expression. This is part of the reason technology has skyrocketed in our age. It is not bad per se, but, especially with internet technology, the culture surrounding human interaction online very quickly misses the dignity of the person behind the screen and sees only their output. It is all seen as extension and self-expression, and the body is merely a tool to be used in this regard. We tend to forget, then, in digital interactions, that this is an embodied encounter between persons.

The Christian vision is different. As Pope St. John Paul II said, “the body, and it alone, is capable of making visible what is invisible, the spiritual and the divine. It was created to transfer into the visible reality of the world the invisible mystery hidden in God from time immemorial, and thus to be a sign of it.” In other words, the body is integral to the human person: that the body both is integrated in and reveals the spiritual dimension of man to others. The soul, then, is not separate from the human body. Yes, it is true, at death the soul is separated from the body. But this is the ultimate and devastating effect of sin. That separation is fundamentally unnatural. The soul needs the body and the body needs the soul.

It is better to look at the body-soul distinction as a real unity. Yes, there is an obvious distinction — we have a body like the animals, but we are able to reason and will, totally unlike them — but there is no real separation. Thus, the body actually has data to tell us about what it means to be human. There is the obvious extensive teaching around what it means to be male and female. The body, if integrated and not separated, is no longer malleable according to our whims, but it requires an interiority and receptivity within the self to be humble and listen to the body, if you will, to reveal the self not only to others, but even to ourselves. If the body is a sign that points to a spiritual reality, then it, too, can even point us to our own spiritual reality, always seen through the lens and mediated through the body. The body, then, no longer becomes something that can change to adapt to my “true self,” but, rather, is essential to my personality and personhood.

The issue with the modern approach to self and body is always going to have an impossible opposition to overcome: the self always needs the body in order to be. It cannot ignore the body. It is integral to personhood. The task of promoting a proper relationship between body and soul seems large and is perhaps, still, at the level of philosophy and theology. Yet it is vital to rediscover this proper relationship and understand how the relationship between body and self has implications beyond the self. It is why we struggle to understand the Church’s teaching on the sacraments, why we do not see the need for mediation between God and creation, etc. For the Church to underpin the vision of herself and of our sacramental reality in how we relate to God, we are going to need to continue to fight the battle to reclaim a more integrated view of body and self.

Father Harrison Ayre is a priest of the Diocese of Victoria, British Columbia. Follow him on Twitter at @FrHarrison. Read more from his Theological Anthropology 101 series here.