Franklin points to the complicated effect that lending money can have on personal relationships. Helping an enemy financially may create gratitude and soften hostility, making reconciliation more likely. Lending to a friend, however, can introduce obligation, embarrassment or disagreement over repayment into a relationship that previously depended on mutual ease and trust.

The saying is deliberately paradoxical and should not be read as a fixed rule about every loan. Many friends lend and repay money without damaging their relationship, while generosity does not necessarily turn an enemy into a friend. Franklin’s broader point is that debt changes the balance between people. Once money is owed, a relationship may involve pressure, dependence or avoidance as well as affection. Financial transactions between people who know one another can therefore have social consequences beyond the value of the money itself.