In quantum mechanics, wave–particle duality is the theory that every particle or quantum entity may be described as either a particle or a wave. It captures the indecency of concepts particle or wave to fully capture the nuances of how quantum-scale objects behave. As Einstein said:

It seems as though we must use sometimes the one theory and sometimes the other, while at times we may use either. We are faced with a new kind of difficulty. We have two contradictory pictures of reality; separately neither of them fully explains the phenomena of light, but together they do.

Our concept of marriage faces a similar dilemma – is it a contract or a covenant?

A contract says I’ll do this for you if and only if you do that for me. It lays out terms, and repercussions if those terms aren’t met. We’re all familiar with contracts from a legal or services perspective – whether joining a gym or setting up an iPhone, we’re bombarded with contracts every day. The ‘contractual-ness’ of marriage is nowhere mo evident than when one is ending it – splitting assets and negotiating terms for shared custody are very contractual transactions.

A covenant on the other hand is a promise no-matter-what. The “standard” Western/Christian marriage vow – for better or worse, for richer or poorer, in sickness and in health – outlines a covenant relationship. This is consistent with many monotheistic religions’ view of the relationship between God and man as a covenant – God’s love is eternal and unconditional, irrespective of man’s sins.

The covenant view of marriage is idealistic but not realistic… at least by itself. With divorce rates in the US hovering near 50%, there’s no question that the covenant marriage is aspirational. Viewing marriage as a contract also seems inadequate in capturing the complexities and ‘best-effort’ nature of a long-term, committed relationship.

So perhaps we need both of these concepts, in tandem, to wrap our heads around the totality of what a modern marriage is. We aspire to a covenant, and fall back to a contract, and spend the day-to-day navigating the purgatory that lies in-between.