Origin and history of crisis

crisis(n.)

early 15c., crise, crisis, "decisive point in the progress of a disease," also "vitally important or decisive state of things, point at which change must come, for better or worse," from Latinized form of Greek krisis "turning point in a disease, that change which indicates recovery or death" (used as such by Hippocrates and Galen), literally "judgment, result of a trial, selection," from krinein "to separate, decide, judge" (reconstructed to be from PIE root *krei- "to sieve," thus "discriminate, distinguish").

The transferred (non-medical) sense is attested by 1620s in English.

Thank Heaven! the crisis—

The danger, is past,

And the lingering illness

Is over at last—

And the fever called "Living"

Is conquer'd at last.

[Poe, "For Annie"]

also from early 15c.

Entries linking to crisis

certain(adj.)

c. 1300, "determined, fixed," from Old French certain "reliable, sure, assured" (12c.), from Vulgar Latin *certanus, extended form of Latin certus "determined, resolved, fixed, settled," of things whose qualities are invariable, "established," also "placed beyond doubt, sure, true, proved; unerring, to be depended upon" (also source of Old French cert, Italian certo, Spanish cierto), originally a variant past participle of cernere "to distinguish, decide," literally "to sift, separate." This Latin verb comes from the PIE root *krei- "to sieve," thus "discriminate, distinguish," which is also the source of Greek krisis "turning point, judgment, result of a trial" (compare crisis).

The transferred sense, in reference to persons, "full of confidence in one's knowledge or judgment, made certain in reference to a matter or thing," is from mid-14c. (it also was a sense in Latin). The meaning "established as true beyond doubt" in English is from c. 1400. The meaning "indefinite, not specifically named, known but not described" is from late 14c.

Different as this seems to be from sense I, it is hardly separable from it in a large number of examples: thus, in [ a certain hour], the hour was quite 'certain' or 'fixed', but it is not communicated to the reader; to him it remains, so far as his knowledge is concerned, quite indefinite; it may have been, as far as he knows, at any hour; though, as a fact, it was at a particular hour. [OED]

Lewis & Short write that Latin certus also was sometimes indefinite, "of things, the certainty of whose existence is given, but whose nature is not more definitely designated, or comes not into consideration ...."

Hence the euphemistic use, attested from mid-18c., as in woman of a certain age "an old maid;" woman of a certain description "disreputable woman;" in a certain condition "pregnant;" a certain disease "venereal disease;" of a certain weight "obese." Used with proper names from 1785, "often conveying a slight shade of disdain" [OED]. Certainer, certainest were common to c. 1750, but have fallen from proper use for some reason. Expression for certain "assuredly" is attested by early 14c.

*krei-

Proto-Indo-European root meaning "to sieve," thus "discriminate, distinguish."

It might form all or part of: ascertain; certain; concern; concert; crime; criminal; crisis; critic; criterion; decree; diacritic; discern; disconcert; discreet; discriminate; endocrine; excrement; excrete; garble; hypocrisy; incertitude; recrement; recriminate; riddle (n.2) "coarse sieve;" secret; secretary.

It might also be the source of: Greek krinein "to separate, decide, judge," krinesthai "to explain;" Latin cribrum "sieve," crimen "judgment, crime," cernere "to sift, distinguish, separate;" Old Irish criathar, Old Welsh cruitr "sieve;" Middle Irish crich "border, boundary;" Old English hriddel "sieve."