doctrinaire

noun

1. A person who stubbornly holds to a philosophy or opinion regardless of its feasibility.

   “And he is not above feeling grave and well-contained satisfaction wherever the socialist doctrinaire has been contradicted by men attempting to practise coöperation in the midst of the competitive system, as in Belgium.”

   “Or, shall we play the doctrinaire, and hint that at thirty-four the tides of life are calmer and cognizant of many sources instead of but one—as at four-and-twenty?”

2. (historical)In France, in 1815–30, one of a school who desired a constitution like that of Britain.

adj

1. Stubbornly holding on to an idea without concern for practicalities or reality.

   “Mr. Chapman began to talk in a loud voice about the situation in the House of Commons. He guffawed at his adversaries. The word doctrinaire—word full of terror to the British mind—reappeared from time to time between his explosions.”

   “We have been long accustomed to consider growth as applied almost exclusively to size in its various aspects. But Nature, who has no doctrinaire ideas, may equally apply it to concentration.”

   “They showed a new and encouraging Parliamentary appreciation that it is time our national transport problems were examined expertly and without doctrinaire prejudice of any sort—or too much attention to the lobbying of some powerful special interests.”

   “The next government should be patient, and wait for the revenues to begin flowing. The course set by Cameron and Osborne is not just doctrinaire. It is also dangerous.”

   “As analysts warned that relying on boosting economic growth to reduce income inequalities could increase disparities, Tory grandees sounded the alarm over what they said risked being an doctrinaire approach.”