Linking yourself harmoniously with another person requires an understanding and appreciation of passion—but not in the way you might expect.

Since sex and relationships are closely related concepts, in their book F*cked, Corinne Fisher and Krystyna Hutchinson expend a fair amount of ink on relationships. They explain that, in order to have a healthy one, you must, must, must believe in your partner, and he or she must, must, must believe in you.

Otherwise, the best symbol for the two of you isn’t a rose . . . but a slice of bread heated on both sides.

“No matter how stupid a passion seems,” Fisher writes, “remember that anything someone feels passionately about cannot be stupid because it’s the reason they get up in the morning.”

Then she makes a joke, presumably to clarify that there are exceptions, but her point remains: you and your partner must respect each other’s passions. You must not ridicule them, explain them away, or urge their abandonment.

The word passion has one of those fascinatingly acrobatic etymologies: the kind that make language lovers swoon. It originally referred to suffering, especially the suffering of Christ, or to oratorios, notably by Bach, about the suffering of Christ. Over several centuries, the word morphed from meaning “suffering” to “a strong emotion or desire for something” to “a strong feeling of sexual love” to “enthusiasm about something.”

But at the root of the word is suffering: a longing for things to be different. A passion is something you cannot happily live without.

What is yours? What is your partner’s? Are you supportive of each other’s passions?