He who betrays once will betray again — the proverb warns that betrayal is not an isolated event but a character trait. Once someone has shown themselves capable of betrayal, trust should not be restored.
This proverb reflects a deeply ingrained Italian distrust of rehabilitation in matters of loyalty. It belongs to a family of Italian sayings that emphasise the immutability of character — the idea that a person's nature is fixed and that past behaviour is the most reliable predictor of future behaviour. The proverb was particularly common in the codes of honour that governed relationships in rural Italian communities from the medieval period through the 19th century, where a single act of treachery could permanently mark a family across generations. Dante's Inferno placed traitors in the very lowest circle of Hell — a theological endorsement of the popular view that betrayal was the worst of sins, worse than violence or lust. The Renaissance courts of Italy, famous for their political backstabbing and double-dealing, produced a generation of writers — from Machiavelli to Guicciardini — who documented betrayal with clinical precision and largely confirmed the popular wisdom that leopards do not change their spots. Today the proverb is most often heard in personal rather than political contexts, invoked when someone decides not to forgive a partner or friend who has broken their trust.
Related to the Dante tradition placing traitors in the ninth circle of Hell (Inferno, cantos XXXII–XXXIV).
A friend advising against reconciliation after a betrayal
Non tornare con lui. Ti ha mentito una volta, ti mentirà ancora. Chi tradisce una volta tradisce sempre.
Do not go back to him. He lied to you once, he will lie again. He who betrays once betrays always.
A businesswoman deciding not to renew a contract
Quell'azienda ci ha copiato i dati due anni fa. Non lavoro più con loro. Chi tradisce una volta tradisce sempre.
That company copied our data two years ago. I no longer work with them. He who betrays once betrays always.
A father warning his daughter
So che lo ami, ma fai attenzione. Chi tradisce una volta tradisce sempre — non dimenticarlo.
I know you love him, but be careful. He who betrays once betrays always — do not forget that.
Reflecting on a political figure
Cambiò partito tre volte in dieci anni. Chi tradisce una volta tradisce sempre — e i suoi nuovi alleati lo scopriranno presto.
He changed party three times in ten years. He who betrays once betrays always — and his new allies will discover it soon.