Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class IV. Words Relating to the Intellectual Faculties
Division (I) Formation of Ideas
Section III. Materials for Reasoning

471. Impossibility.

   NOUN:IMPOSSIBILITY &c. adj.; what cannot be, what can never be; sour grapes; hopelessness [See Hopelessness]; infeasibility, infeasibleness, impracticality; discrepancy (disagreement) [See Amorphism].
  [COMPARISONS] Canute (commanding the tide), Mrs. Partington (and her mop).
   VERB:BE IMPOSSIBLE &c. adj.; have no chance whatever.
  ATTEMPT IMPOSSIBILITIES; square the circle, find the elixir of life, discover the philosopher’s stone, discover the grand panacea, find the fountain of youth, discover the secret of perpetual motion; wash a blackamoor white; skin a flint; make a silk purse out of a sow’s ear, make bricks without straw; have nothing to go upon; weave a rope of sand, build castles in the air, prendre la lune avec les dents [F.], extract sunbeams from cucumbers, milk a he-goat into a sieve, catch a weasel asleep, rompre l’anguille au genou [F.], be in two places at once; gather grapes from thorns, fetch water in a sieve, catch wind in cabbage nets, fling eels by the tail, make cheese of chalk.
   ADJECTIVE:IMPOSSIBLE; not possible [See Possibility]; absurd, contrary to reason; at variance with the facts; unlikely; unreasonable [See Intuition. Sophistry]; incredible [See Unbelief. Doubt]; beyond the bounds of -reason, – possibility; from which reason recoils; visionary; inconceivable (improbable) [See Improbability]; prodigious &c. (wonderful) [See Wonder]; unimaginable, inimaginable [obs.], not to be thought of, unthinkable.
  IMPRACTICABLE, unachievable; unfeasible, infeasible; insuperable; insurmountable or unsurmountable, unattainable, unobtainable; out of reach, out of the question; not to be had; beyond control; desperate (hopeless) [See Hopelessness]; incompatible [See Disagreement]; inaccessible, uncomeatable [colloq.], impassable, impervious, innavigable, inextricable; self-contradictory.
  out of -, beyond- one’s -power, – depth, – reach, – grasp; too much for; ultra crepidam [L.].
  1. The grapes are sour.
  2. Non possumus.
  3. Non nostrum tantas componere lites.—Vergil
  4. Chercher une aiguille dans une botte de foin.
  5. Il a le mer à boire.
  6. Few things are impossible to diligence and skill.—Johnson
  7. It is not a lucky word, this same impossible.—Carlyle