casuistry
noun·/ˈkæʒ.ju.ɪ.stri/
1. The careful reasoning of moral cases, weighing duties and circumstances where rules collide—an attempt to make conscience practical (ethics; historical). At its best, casuistry is precision applied to lived complexity.
Their debate was casuistry in the old sense: not evasion, but an honest struggle to do right in crooked conditions.
2. Sophistical or overly subtle reasoning used to justify what one already wants to do (often pejorative).
He called it principle, but everyone heard the casuistry—logic bent into a convenient shape.
Etymology
From Latin casus “case,” via casuist and learned moral theology. The word’s double reputation comes from its double possibility: nuance can illuminate, or it can excuse.
Related Words
sophistryspecious reasoning; a frequent synonym in the pejorative sense
ethicsthe larger field casuistry inhabits
scruplethe hesitation casuistry often tries to resolve
special pleadinga modern label for casuistry at its worst