the end justifies the means
Widely attributed to Machiavelli's The Prince, which does reflect this philosophy but does not use the phrase in this wording. A possible source is Ovid's Heroides (ca. 10 BC), which says exitus ācta probat (“the outcome justifies the deeds”). However, its use there is quite likely to have an opposite meaning of outcomes proving means were unjustified, based on its context.
- Morally wrong actions are sometimes necessary to achieve morally right outcomes; actions can be considered morally right or wrong only by virtue of the morality of the outcome.