nature of the beast

English

(idiomatic, with "the") The unchangeable nature of something.
- 1863, Sheridan Le Fanu, The House by the Churchyard:
  This slight way of treating both his book and his ancestors nettled little Puddock – who never himself took a liberty, and expected similar treatment – but he knew Sturk, the nature of the beast, and he only bowed grandly […]
- 1884, Frank de Yeaux Carpenter, Round About Rio:
  "A little slow, that's all; but that's the nature of the beast."

unchangeable nature

Dutch: aard van het beestje m
Finnish: kuulua luontoon (verb phrase: "to be the nature of the beast"), todellinen luonne (unidiomatic)
French: ordre des choses (fr) m
Polish: natura sprawy f