CASUIST
casuist, sophist
(noun) someone whose reasoning is subtle and often specious
Source: WordNet® 3.1
Etymology
Noun
casuist (plural casuists)
(ethics) A person who resolves cases of conscience or moral duty.
Someone who attempts to specify exact and precise rules for the direction of every circumstance of behaviour.
One who is skilled in, or given to, casuistry.
Source: Wiktionary
Cas"u*ist, n. Etym: [L. casus fall, case; cf. F. casuiste. See
Casual.]
Definition: One who is skilled in, or given to, casuistry.
The judment of any casuist or learned divine concerning the state of
a man's soul, is not sufficient to give him confidence. South.
Cas"u*ist, v. i.
Definition: To play the casuist. Milton.
Source: Webster’s Unabridged Dictionary 1913 Edition