Casuistry

[Little_Girl]

The science or doctrine of dealing with cases of
conscience, of resolving questions of right or wrong in conduct, or
determining the lawfulness or unlawfulness of what a man may do by
rules and principles drawn from the Scriptures, from the laws of
society or the church, or from equity and natural reason; the
application of general moral rules to particular cases.

[Monty]

the use of clever arguments to trick people