Should You Marry Your Best Friend? Thomas Aquinas Says Yes!

Introduction

Should you marry your best friend? According to St. Thomas Aquinas, true marriage is more than a legal or biological union it's the highest form of friendship. Rooted in both natural law and divine grace, this conjugal friendship is what sustains a marriage through time, making friendship not optional, but essential to love that endures

Should you marry your best friend? It’s an age-old cultural debate with strong feelings on both sides, but interestingly enough it’s a question that has already been settled for us in the middle ages by none other than the Angelic Doctor himself. For St. Thomas Aquinas, the key to understanding the nature of marriage itself is not primarily through the lens of legal obligations and rights that are incumbent upon the societal duty to propagate the human species, but through the lens of friendship. This may come as a surprise to some readers. After all, St. Thomas is famously known for advancing a natural law framework within which to understand sexual ethics which centers on the indispensable role sacred procreation has in defining marriage. However, St. Thomas did not subscribe to any form of biological reductionism. That is, he did not  believe that marriage was reducible to the biological capacity of human beings to reproduce after their own kind. Rather, he held that marriage at its core is, above all, to be defined as a conjugal friendship and that it is through this framework that all of the obligations, rights, duties, and benefits of marriage become intelligible. In fact, St. Thomas goes so far as to say that the bond which unites a husband and wife is the “greatest of friendship”.

Now friendship in its purest expression for St. Thomas and the Aristotelian tradition more broadly does not refer to just any shared bond or amicable relationship between two or more parties. Though many friendships can be described precisely along those lines, St. Thomas would consider these imperfect friendships precisely because they are founded on some form of utility or mutual benefit each party receives from the relationship, even if that benefit is the pleasure one gets from the companionship itself. A perfect friendship, on the other hand, is a bond which elicits in each party a permanent habit or disposition of the soul which has the good of each other as its immovably fixed object.  Now this notion of friendship is realized perfectly and supernaturally in the sacrament of marriage. For in marriage, each spouse is by Divine power supernaturally ordained toward the other for the sake of each other’s spiritual and temporal good. This is friendship of the highest and noblest order. As St. Thomas puts it, 

“There seems to be the greatest friendship between husband and wife, for they are united not only in the act of fleshly union, which produces a certain gentle association even among beasts, but also in the partnership of the whole range of domestic activity. Consequently, as an indication of this, man must even “leave his father and mother” for the sake of his wife, as is said in Genesis (2:24)." [1]

In marriage, then, while sexual union or conjugality designates this particular perfect friendship as the kind of perfect friendship that it is, just as equilaterality designates a particular triangle as the kind of triangle that it is, conjugality remains a specification of friendship. Therefore, not only is it advisable that spouses first and foremost ground their mutual compatibility in the quality of their friendship, it is imperative that they do so, without of course erasing the distinctive roles of husband and wife within the life of the marriage. Failing to do this loses sight of what fundamentally makes a marriage. In very short order as the thrilling novelty of physical infatuation begins to subside, it is the quality of the underlying friendship which will remain and therefore determine the quality of the marriage itself. For this reason, it is vitally important that spouses carve out as much time as possible to focus exclusively on cultivating the quality of this friendship by exploring shared interests, engaging in regular non-pragmatic conversation for its own sake, planning date nights, etc. This daily work of relational cultivation will be worth its weight in gold as the decades pass, youthfulness fades, and as children mature, for if this is done well, you will have built a bond of intimacy that is so strong and pure that it will have transcended the physical conjugality of marriage altogether and will persist even in the New Heaven and the New Earth. You may not therefore have your marriage in heaven, but you will still have your best friend. 

References:

1. Summa Contra Gentiles III, ii, 126, vi