“Love one another but make not a bond of love: let it rather be a moving sea between the shores of your souls,” the great Lebanese-American poet, philosopher, and painter Kahlil Gibran counseled in what remains the finest advice on the secret to a loving and lasting relationship.

Our paradoxical longing for intimacy and independence is a diamagnetic force — it pulls us toward togetherness and simultaneously repels us from it with a mighty magnet that, if unskillfully handled, can rupture a relationship and break a heart. Under this unforgiving magnetism, it becomes an act of superhuman strength and self-transcendence to give space to the other when all one wants is closeness. And yet this difficult act may be the very thing — perhaps the only thing — that saves the relationship over and over.

Two decades before Gibran, at the dawn of the twentieth century, another great poet of abiding insight into the turbulences of the human heart contemplated this predicament. In a letter to the trailblazing German expressionist painter Paula Modersohn-Becker, Rainer Maria Rilke (December 4, 1875–December 29, 1926) offered some spectacular advice on managing the bipolar pull of autonomy and togetherness in a way that assures the longevity of any close bond and protects love from self-destruction. The passages appear in the wonderful poetry and prose anthology Rilke on Love and Other Difficulties: Translations and Considerations (public library), selected and translated by the scholar and philosopher John Mood.

Rilke writes:

I hold this to be the highest task of a bond between two people: that each should stand guard over the solitude of the other. For, if it lies in the nature of indifference and of the crowd to recognize no solitude, then love and friendship are there for the purpose of continually providing the opportunity for solitude. And only those are the true sharings which rhythmically interrupt periods of deep isolation.

A century before psychologist Esther Perel asserted in her landmark book on the central paradox of relationships that “love rests on two pillars: surrender and autonomy” because “our need for togetherness exists alongside our need for separateness,” Rilke considers how our cultural constructs around what it means to be coupled obstruct happiness in union:

It is a question in marriage, to my feeling, not of creating a quick community of spirit by tearing down and destroying all boundaries, but rather a good marriage is that in which each appoints the other guardian of his solitude, and shows him this confidence, the greatest in his power to bestow. A togetherness between two people is an impossibility, and where it seems, nevertheless, to exist, it is a narrowing, a reciprocal agreement which robs either one party or both of his fullest freedom and development. But, once the realization is accepted that even between the closest human beings infinite distances continue to exist, a wonderful living side by side can grow up, if they succeed in loving the distance between them which makes it possible for each to see the other whole and against a wide sky! Therefore this too must be the standard for rejection or choice: whether one is willing to stand guard over the solitude of a person and whether one is inclined to set this same person at the gate of one’s own solitude, of which he learns only through that which steps, festively clothed, out of the great darkness.

This principle, Rilke points out, holds true not only in marriage but in any close relationship and any bond desired to last a lifetime:

All companionship can consist only in the strengthening of two neighboring solitudes, whereas everything that one is wont to call giving oneself is by nature harmful to companionship: for when a person abandons himself, he is no longer anything, and when two people both give themselves up in order to come close to each other, there is no longer any ground beneath them and their being together is a continual falling… Once there is disunity between them, the confusion grows with every day; neither of the two has anything unbroken, pure, and unspoiled about him any longer… They who wanted to do each other good are now handling one another in an imperious and intolerant manner, and in the struggle somehow to get out of their untenable and unbearable state of confusion, they commit the greatest fault that can happen to human relationships: they become impatient. They hurry to a conclusion; to come, as they believe, to a final decision, they try once and for all to establish their relationship, whose surprising changes have frightened them, in order to remain the same now and forever (as they say).

Two millennia after Epictetus offered the Stoic cure for heartbreak in the recognition of the temporality and flux of all things, Rilke adds:

Self-transformation is precisely what life is, and human relationships, which are an extract of life, are the most changeable of all, rising and falling from minute to minute, and lovers are those in whose relationship and contact no one moment resembles another.

The outliers impervious to this supreme challenge of love are rare, Rilke notes; for the rest of us, there is only the hard, necessary work of love:

There are such relationships which must be a very great, almost unbearable happiness, but they can occur only between very rich natures and between those who, each for himself, are richly ordered and composed; they can unite only two wide, deep, individual worlds. […] For one human being to love another: that is perhaps the most difficult of all our tasks, the ultimate, the last test and proof, the work for which all other work is but preparation.

Complement this particular portion of the altogether beautiful and healing Rilke on Love and Other Difficulties with Anna Dostoyevskaya on the secret to a happy marriage, Virginia Woolf on what makes love last, and Kahlil Gibran on the courage to weather the uncertainties of love, then revisit Rilke on the lonely patience of creative work, what it takes to be an artist, why we read, and how hardship enlarges us.