Anyone who has received an unexpectedly lavish present knows the peculiar discomfort that follows the delight. What do I owe now? Should I give something equally expensive in return, and how soon? Idunn Varga's The Unreturnable begins with this small social panic and builds from it a surprisingly large argument. Gifts, she contends, are never free, and the fantasy that they should be has made us worse at giving, worse at receiving and lonelier than we need to be.

Her first guide is the French anthropologist Marcel Mauss, whose 1925 essay The Gift studied exchange in societies from the Pacific Northwest to Melanesia. Mauss argued that gifts carry three obligations: to give, to receive and to reciprocate. Far from being spontaneous acts of pure generosity, gifts in these societies wove people into lasting relationships of mutual obligation. To refuse a gift, or to fail to return one, was to refuse the relationship itself. Varga suggests we have never really escaped this logic.

Her second guide is Seneca, whose long treatise On Benefits is one of the most practical works of ancient ethics. Seneca was fascinated by the moral psychology of giving and receiving, and he offered a memorable asymmetry: the giver should forget the benefit at once, while the receiver should never forget it. Varga reads this as a wise division of labour. Obligation exists, but it is held on one side only, and held lightly, as gratitude rather than debt.

Against the pure gift

The most ambitious chapter takes on the ideal of the pure gift, a gift that expects nothing and creates no bond. Varga notes that Jacques Derrida argued such a gift may be impossible, since the moment a gift is recognised as a gift it enters a circle of exchange. Rather than mourn this, she welcomes it. A gift that created no bond would be closer to a transaction than a relationship. The small debt is not the gift's flaw. It is the thread that ties two people together.

A gift that asks for nothing is a gift that wants nothing to do with you.

The book is weaker when it turns to modern consumer culture. Her criticism of gift cards, wish lists and return receipts is witty, but it occasionally tips into snobbery, and she seems reluctant to admit that practical gifts can also be loving ones. A chapter on corporate gifting feels like a separate essay, bolted on. Readers who have spent December navigating tight family budgets may think her disdain for the returnable jumper comes a little too easily.

Still, the central argument is both original and useful. Varga's closing advice is to give things that cannot be exchanged or returned: time, a handwritten letter, a meal cooked for someone in particular, a favour offered before it is requested. These are gifts that create exactly the kind of gentle obligation she values, the kind that makes people want to see each other again. They are also, pointedly, gifts that money alone cannot buy.

The Unreturnable is not a perfect book, but it is a generous one, which seems appropriate. It will change the way you think about the next present you give, and perhaps the way you feel about the next one you receive. Its lesson, borrowed from Seneca and Mauss and made new, is that being in someone's debt is not a burden to be cleared as quickly as possible. It is one of the ways we belong to each other.