Obdurate

As the title of the blog included etymology I suppose I should include a post about it. The other day I was reading The Institutes of Christian Religion — which one should never read without a dictionary nearby — when I came across the word obdurate which is apparently very similar to obstinate. My Oxford dictionary gives this etymology

ORIGIN late Middle English (originally in the sense [hardened in sin, impenitent] ): from Latin obduratus, past participle of obdurare, from ob- ‘in opposition’ + durare ‘harden’ (from durus ‘hard’ ).

Obstinate comes from the Latin to persist.

On a further note there’s even a useful note at stubborn delineating the usage and shades of meaning of the related words.

THE RIGHT WORD
If you’re the kind of person who takes a stand and then refuses to back down, your friends might say you have a stubborn disposition, a word that implies an innate resistance to any attempt to change one’s purpose, course, or opinion.

People who are stubborn by nature exhibit this kind of behavior in most situations, but they might be obstinate in a particular instance (: a stubborn child, he was obstinate in his refusal to eat vegetables). Obstinate implies sticking persistently to an opinion, purpose, or course of action, especially in the face of persuasion or attack.
While obstinate is usually a negative term, dogged can be either positive or negative, implying both tenacious, often sullen, persistence (: dogged pursuit of a college degree, even though he knew he would end up in the family business) and great determination ( | dogged loyalty to a cause).

Obdurate usually connotes a stubborn resistance marked by harshness and lack of feeling (: obdurate in ignoring their pleas), while intractable means stubborn in a headstrong sense and difficult for others to control or manage ( | intractable pain).

No matter how stubborn you are, you probably don’t want to be called pertinacious, which implies persistence to the point of being annoying or unreasonable (: a pertinacious panhandler).